Skip to main content
U.S. flag

An official website of the United States government

Leo Nico, Ph.D. (Former Employee)

Science and Products

Filter Total Items: 55

Occurrence of a reproducing wild population of Channa aurolineata (Pisces: Channidae) in the Manatee River drainage, Florida

We report on the discovery of a wild, reproducing population of Channa aurolineata (Pisces: Channidae) in west-central Florida (USA), and first documented occurrence of snakeheads in the Gulf Coast region. Channa aurolineata is a large, predatory fish of the bullseye snakehead “Marulius group” species complex from Asia. Adult and juvenile specimens were captured in June 2020 in a 1.8-hectare pond
Authors
Leo Nico, Matthew Neilson, Robert H. Robins, John M. Pfeiffer, Matthew Kail, Zachary S. Randall, Eric A. Johnson
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Evaluating establishment success of non-native fishes introduced to inland aquatic habitats of tropical Pacific islands

An information-theoretic approach was used to evaluate non-native freshwater fish species introduced to insular habitats of Hawaii and Guam comparing successful establishments vs. failures. Since the late 1800s, as many as 81 non-native freshwater fish species have been recorded as introduced to Hawaii and Guam (combined) and 50 (62%) of these are documented as having one or more established popul
Authors
Stephen Walsh, Leo Nico, Mark W. Miller
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Discovery of a reproducing wild population of the swamp eel Amphipnous cuchia (Hamilton, 1822) in North America

We report discovery of an established population of the Asian swamp eel Amphipnous cuchia (Hamilton, 1822) in Bayou St. John, an urban waterway in New Orleans, Louisiana, USA. This fish, commonly referred to as cuchia (kuchia), is a member of the family Synbranchidae and is native to southern and southeastern Asia. Recently-used synonyms include Monopterus cuchia and Ophichthys cuchia. We collecte
Authors
Frank Jordan, Leo Nico, Krystal Huggins, Peter J. Martinat, Dahlia A. Martinez, Victoria L. Rodrigues
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Asian swamp eels in North America linked to the live-food trade and prayer-release rituals

We provide a history of swamp eel (family Synbranchidae) introductions around the globe and report the first confirmed nonindigenous records of Amphipnous cuchia in the wild. The species, native to Asia, is documented from five sites in the USA: the Passaic River, New Jersey (2007), Lake Needwood, Maryland (2014), a stream in Pennsylvania (2015), the Tittabawassee River, Michigan (2017), and Meado
Authors
Leo Nico, Jay V. Kilian, Andrew J. Ropicki, Matthew Harper
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Environmental DNA assays for invasive populations of the Black Carp, Mylopharyngodon piceus, in North America

The Black Carp, Mylopharyngodon piceus, is an increasingly widespread invasive species in North America that threatens freshwater mussel populations. We developed four qPCR assays for detecting environmental DNA (eDNA) from these Black Carp populations. Assays were designed to target four mitochondrial DNA loci and were based on 34 complete mitochondrial genome sequences, including 29 generated in
Authors
Xin Guan, E.M. Monroe, K.D. Bockrath, Erica L. Mize, C.B. Rees, Denise L. Lindsay, Kelly L. Baerwaldt, Leo Nico, Richard F. Lance
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Serrasalmidae — Piranhas and Pacus

The family Serrasalmidae is a morphologically and ecologically diverse group of South American freshwater fishes consisting of 16 genera and about 91 valid species. This chapter is a summary of the current state of knowledge on serrasalmid taxonomy, species richness, and ecology, and provides an identification key to the genera and references to relevant literature for species-level identification
Authors
Leo Nico, Michel Jegu, Marcelo C Andrade
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions

The Tampa Bay region of Florida (USA) is a hot spot for non-native freshwater fishes. However, published information on most non-native fishes in the basin is not current. Systematic sampling efforts targeting non-native fishes in the region were conducted from 2013–2015 by the University of Florida Tropical Aquaculture Laboratory. Data from these recent surveys were analyzed, along with historic
Authors
Katelyn M. Lawson, Quenton M. Tuckett, Jared L. Ritch, Leo Nico, Pam Fuller, Richard E. Matheson, Jeffrey E. Hill
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Detection limits of quantitative and digital PCR assays and their influence in presence-absence surveys of environmental DNA

A set of universal guidelines is needed to determine the limit of detection (LOD) in PCR-based analyses of low concentration DNA. In particular, environmental DNA (eDNA) studies require sensitive and reliable methods to detect rare and cryptic species through shed genetic material in environmental samples. Current strategies for assessing detection limits of eDNA are either too stringent or subjec
Authors
Margaret Hunter, Robert M. Dorazio, John S. Butterfield, Gaia Meigs-Friend, Leo Nico, Jason A. Ferrante
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Evaluating the piscicide rotenone as an option for eradication of invasive Mozambique tilapia in a Hawaiian brackish-water wetland complex

Mozambique tilapia Oreochromis mossambicus were recently discovered in ‘Aimakapā Fishpond, a 12-hectare brackish-water wetland complex in Kaloko-Honokōhau National Historical Park, on the Island of Hawai’i. As a possible eradication method, we evaluated rotenone, a natural piscicide used in fish management and the active ingredient in plants traditionally used by indigenous Hawaiians for capturing
Authors
Leo Nico, Ronald A. Englund, Howard L. Jelks
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Genetic analysis of invasive Asian Black Carp (Mylopharyngodon piceus) in the Mississippi River Basin: evidence for multiple introductions

Invasive Asian Black Carp (Mylopharyngodon piceus) have been present in USA aquaculture facilities since the 1980s and wild Black Carp have been found in the Mississippi River Basin since the early 1990s. This study characterizes the genetic diversity and relatedness of the Basin’s Black Carp and clarifies the introduction history. Analyses focused on three mitochondrial markers (control region, c
Authors
Margaret E. Hunter, Leo G. Nico
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

One carp, two carp: are there more carp in the Wailoa River?

The February, 2015 issue of Hawaii Fishing News included the annual list of Hawai`i records for the largest fish of various species caught in the state. Among the new records was one for a 15-pound grass carp (Ctenopharyngodon idella) caught by Avery Berido in the Wailoa River at Hilo on September 13, 2013. A photograph taken by Mr. Berido of the record grass carp garnered our attention because pi
Authors
Bruce C Mundy, Leo Nico, Annette Tagawa
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States

In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 w
Authors
Rebecca A. Cole, Anindo Choudhury, Leo G. Nico, Kathryn M. Griffin
By
Ecosystems Mission Area, National Wildlife Health Center, Wetland and Aquatic Research Center

Non-USGS Publications**

Keevin, T.M., L.G. Nico, and D.C. Taphorn. 2015. Obituary: Jamie Edward Thomerson (1935-2015). Copeia 2015:1096-1101. (pdf available from author)
Nico, L.G. & S.J. Walsh. 2011. Nonindigenous freshwater fishes on tropical Pacific islands: a review of eradication efforts. Pages 97-107 in C. R. Veitch, M. N. Clout, and D. R. Towns, editors. Island Invasives: Eradication and Management. International Union for Conservation of Nature (IUCN), Gland, Switzerland and Centre for Biodiversity and Biosecurity (CBB), Auckland, New Zealand.
Nico, L.G., H.L. Jelks, & T. Tuten. 2009. Non-Native suckermouth armored catfishes in Florida: Description of nest burrows and burrow colonies with assessment of shoreline conditions. Aquatic Nuisance Species Research Bulletin 9: 1-30. [Link]
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O.M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2006. Lista de los peces identificados para la cuenca del río Ventuari. Apéndice 7) p 214- 223 in C.A. Lasso, J.C. Señaris, L.E. Alonsi, & A.L. Flores (editors). Rapid assessment of the biodiversity of the aquatic ecosystems of the Ventuari and its confluences with the Orinoco River, Amazonas State, Venezuela. RAP Bulletin of Biological Assessment 30. Conservation International, Washington, D.C.
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O.M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2006. Lasso-Alcalá, O., DoNascimiento C., & Milani, N.bPeces del bajo río Ventuari: Resultados del Proyecto de Investigación Biocentro-FLASA-Terra Parima (Capítulo 8), p 123-128. in: Lasso, C., Señarìs, J., Alonso, L., & Flores, A. (Editores). Evaluación Rápida de la Biodiversidad de los Ecosistemas Acuáticos en la Confluencia de los ríos Orinoco y Ventuari, Estado Amazonas (Venezuela). Boletín RAP de Evaluación Biológica 30. Conservation International. Washington DC.
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O. M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2005. Fishes of the Ventuari River drainage, Amazonas State, Venezuela: 1) results of investigation; and 2) list of fish species. Pages 123-128 and 214-223, in C.A. Lasso, J.C. Señaris, L.E. Alonsi, and A.L. Flores, (editors). Rapid assessment of the biodiversity of the aquatic ecosystems of the Ventuari and its confluences with the Orinoco River, Amazonas State, Venezuela. RAP Bulletin of Biological Assessment, volume 30. Conservation International, Washington, D.C.
Fuller, P., L.G. Nico, & J.D. Williams. 1999. Nonindigenous fishes introduced to inland waters of the United States. American Fisheries Society Special Publication 27. American Fisheries Society, Special Publication 27, Bethesda, Maryland. 620 pp. [Link]
Nico, L.G., & J.E. Thomerson. 1989. Ecology, food habits and spatial interactions of Orinoco Basin annual killifish. Acta Biologica Venezuelica 12 (3-4): 106-120. (pdf available from Leo Nico)
Nico, L.G. 1989. Geographic distribution: Siren intermedia nettingi. SSAR Herpetological Review 20(1): 11.
Nico, L.G., & D.C. Taphorn. 1988. Food habits of piranhas in the low llanos of Venezuela. BioTropica 20(4): 311-321.
Nico, L.G., D.C. Taphorn & J.E. Thomerson. 1987. Limnological data on the habitat of annual fishes (Cyprinodontidae) in the Venezuelan Llanos with a key to fish identification. BioLlania 5: 129-144. (In Spanish.) (pdf available from author)
Nico, L.G., & D.C. Taphorn. 1986. Those bitin' fish from South America. Tropical Fish Hobbyist 34 (4): 24-27,30-34,36,40-41,56-57. (pdf available from author)
Nico, L.G., & D.C. Taphorn. 1985. Diet of Acestrorhynchus microlepis (Pisces: Characidae) in the low llanos of Venezuela. Copeia1985(3): 794-796.
Nico, L.G., & D.C. Taphorn. 1984. Biology of the tropical drum, Plagioscion squamosissimus, in the "Fernando Corrales" module of UNELLEZ, Apure State. Revista UNELLEZ de Ciencia y Tecnologia, No. 2, pp. 31-39. (In Spanish.)
Nico, L.G., & D.C. Taphorn. 1984. Limnology of Orinoco Basin annual killifish pools. Journal of the American Killifish Association, Technical Paper 24: 3-16.
Nico, L.G. 1983. Avian ecological investigation of the Horseshoe Lake Recreation Area. Southern Illinois University, Edwardsville. Final report submitted to Illinois Department of Conservation. i-iv + 80 p + 4 appendices. (pdf available from author)
Nico, L.G. 1981. Avian ecological investigation of Kaskaskia River Fish and Wildlife Area. Southern Illinois University, Edwardsville. Final report submitted to Illinois Department of Conservation. i-iii + 72 pp. (pdf available from author)

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

link
Live Asian carp on display in a U.S. food market

Survey and Assessment of Live Food Markets as an Invasion Pathway

Live food markets may be a source of the increasing number of non-native wild invertebrate and fish species, like Asian swamp eels and snakeheads. USGS is surveying such markets around the United States to identify and document species that might be of concern if released live into the wild to assess if the live food market is a possible invasion pathway.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Survey and Assessment of Live Food Markets as an Invasion Pathway

Live food markets may be a source of the increasing number of non-native wild invertebrate and fish species, like Asian swamp eels and snakeheads. USGS is surveying such markets around the United States to identify and document species that might be of concern if released live into the wild to assess if the live food market is a possible invasion pathway.
Learn More
link
USGS biologists sample fish and macroinvertebrates from Streams in Palau

Risk Analysis of Invasive Freshwater Fishes in Hawaii and Micronesia

Invasive species threaten biodiversity around the world, especially on islands. USGS scientists are helping to identify fish species that have the greatest potential to invade the fresh waters of Microneisa.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Risk Analysis of Invasive Freshwater Fishes in Hawaii and Micronesia

Invasive species threaten biodiversity around the world, especially on islands. USGS scientists are helping to identify fish species that have the greatest potential to invade the fresh waters of Microneisa.
Learn More
link
Parasites of Imported and Non-Native Wild Asian Swamp Eels

Parasites of Imported and Non-Native Wild Asian Swamp Eels

In parts of Asia, wild-caught and aquaculture-reared swamp eels are widely consumed as food by humans and are a common source of human gnathostomiasis, a food-borne zoonosis caused by parasitic nematodes of the genus Gnathostoma spp. In humans, the larvae of these nematodes can cause tissue damage and, in some instances, death. Over the past two decades, many thousands of Asian swamp eels have...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Parasites of Imported and Non-Native Wild Asian Swamp Eels

In parts of Asia, wild-caught and aquaculture-reared swamp eels are widely consumed as food by humans and are a common source of human gnathostomiasis, a food-borne zoonosis caused by parasitic nematodes of the genus Gnathostoma spp. In humans, the larvae of these nematodes can cause tissue damage and, in some instances, death. Over the past two decades, many thousands of Asian swamp eels have...
Learn More
link
Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on t

Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on the Island of Hawai’i

Mozambique tilapia, a highly invasive non-native fish of the family Cichlidae, were discovered in a wetland in Kaloko-Honokohau National Historical Park on the Big Island of Hawai'i. As the U.S. National Park Service works to restore the natural communities and functions of wetland ecosystems on the island, the eradication of the tilapia population is considered necessary to fully achieve wetland...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on the Island of Hawai’i

Mozambique tilapia, a highly invasive non-native fish of the family Cichlidae, were discovered in a wetland in Kaloko-Honokohau National Historical Park on the Big Island of Hawai'i. As the U.S. National Park Service works to restore the natural communities and functions of wetland ecosystems on the island, the eradication of the tilapia population is considered necessary to fully achieve wetland...
Learn More
link
Black carp sample being preserved for genetic study

Genetic Analysis of Wild and Captive Black Carp in the Mississippi River Basin

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Wetland and Aquatic Research Center
link

Genetic Analysis of Wild and Captive Black Carp in the Mississippi River Basin

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.
Learn More

Variables pertaining to establishment success of non-native fishes introduced to the Hawaiian Islands and Guam for use in risk analysis modeling

Data represent dependent and independent variables used in logistic modeling for a study entitled "Evaluating Establishment Success of Non-native Fishes Introduced to Inland Aquatic Habitats of Tropical Pacific Islands." The phases of invasion of nonnative species are transport, introduction, establishment, and spread. To understand likelihood of establishment of species moved to new regions, inve
By
Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Occurrence of live Asian swamp eels in live food markets in USA derived from 2001-2018 surveys

The dataset consists of information on the occurrence of Asian swamp eels in live food markets. The data are from original surveys conducted by Leo G. Nico and colleagues. The surveys were conducted across the USA over the period 2001 to 2018. The dataset includes summary data on the numbers of markets surveyed each year, numbers and names of cities/metropolitan areas where surveys were conducted,
By
Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions-Data

This dataset provides supporting information for the species distribution data used in the associated manuscript. Collections of five non-native fish species were made by a number of institutions, and several capture techniques were used. This dataset also includes number of individuals of each species captured at each locality.
By
Wetland and Aquatic Research Center
Image: Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass Asian Swamp Eels: Predation on Juvenile Largemouth Bass
Asian Swamp Eels: Predation on Juvenile Largemouth Bass
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass Asian Swamp Eels: Predation on Juvenile Largemouth Bass
Asian Swamp Eels: Predation on Juvenile Largemouth Bass
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)

Science and Products

Filter Total Items: 55

Occurrence of a reproducing wild population of Channa aurolineata (Pisces: Channidae) in the Manatee River drainage, Florida

We report on the discovery of a wild, reproducing population of Channa aurolineata (Pisces: Channidae) in west-central Florida (USA), and first documented occurrence of snakeheads in the Gulf Coast region. Channa aurolineata is a large, predatory fish of the bullseye snakehead “Marulius group” species complex from Asia. Adult and juvenile specimens were captured in June 2020 in a 1.8-hectare pond
Authors
Leo Nico, Matthew Neilson, Robert H. Robins, John M. Pfeiffer, Matthew Kail, Zachary S. Randall, Eric A. Johnson
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Evaluating establishment success of non-native fishes introduced to inland aquatic habitats of tropical Pacific islands

An information-theoretic approach was used to evaluate non-native freshwater fish species introduced to insular habitats of Hawaii and Guam comparing successful establishments vs. failures. Since the late 1800s, as many as 81 non-native freshwater fish species have been recorded as introduced to Hawaii and Guam (combined) and 50 (62%) of these are documented as having one or more established popul
Authors
Stephen Walsh, Leo Nico, Mark W. Miller
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Discovery of a reproducing wild population of the swamp eel Amphipnous cuchia (Hamilton, 1822) in North America

We report discovery of an established population of the Asian swamp eel Amphipnous cuchia (Hamilton, 1822) in Bayou St. John, an urban waterway in New Orleans, Louisiana, USA. This fish, commonly referred to as cuchia (kuchia), is a member of the family Synbranchidae and is native to southern and southeastern Asia. Recently-used synonyms include Monopterus cuchia and Ophichthys cuchia. We collecte
Authors
Frank Jordan, Leo Nico, Krystal Huggins, Peter J. Martinat, Dahlia A. Martinez, Victoria L. Rodrigues
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Asian swamp eels in North America linked to the live-food trade and prayer-release rituals

We provide a history of swamp eel (family Synbranchidae) introductions around the globe and report the first confirmed nonindigenous records of Amphipnous cuchia in the wild. The species, native to Asia, is documented from five sites in the USA: the Passaic River, New Jersey (2007), Lake Needwood, Maryland (2014), a stream in Pennsylvania (2015), the Tittabawassee River, Michigan (2017), and Meado
Authors
Leo Nico, Jay V. Kilian, Andrew J. Ropicki, Matthew Harper
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Environmental DNA assays for invasive populations of the Black Carp, Mylopharyngodon piceus, in North America

The Black Carp, Mylopharyngodon piceus, is an increasingly widespread invasive species in North America that threatens freshwater mussel populations. We developed four qPCR assays for detecting environmental DNA (eDNA) from these Black Carp populations. Assays were designed to target four mitochondrial DNA loci and were based on 34 complete mitochondrial genome sequences, including 29 generated in
Authors
Xin Guan, E.M. Monroe, K.D. Bockrath, Erica L. Mize, C.B. Rees, Denise L. Lindsay, Kelly L. Baerwaldt, Leo Nico, Richard F. Lance
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Serrasalmidae — Piranhas and Pacus

The family Serrasalmidae is a morphologically and ecologically diverse group of South American freshwater fishes consisting of 16 genera and about 91 valid species. This chapter is a summary of the current state of knowledge on serrasalmid taxonomy, species richness, and ecology, and provides an identification key to the genera and references to relevant literature for species-level identification
Authors
Leo Nico, Michel Jegu, Marcelo C Andrade
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions

The Tampa Bay region of Florida (USA) is a hot spot for non-native freshwater fishes. However, published information on most non-native fishes in the basin is not current. Systematic sampling efforts targeting non-native fishes in the region were conducted from 2013–2015 by the University of Florida Tropical Aquaculture Laboratory. Data from these recent surveys were analyzed, along with historic
Authors
Katelyn M. Lawson, Quenton M. Tuckett, Jared L. Ritch, Leo Nico, Pam Fuller, Richard E. Matheson, Jeffrey E. Hill
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Detection limits of quantitative and digital PCR assays and their influence in presence-absence surveys of environmental DNA

A set of universal guidelines is needed to determine the limit of detection (LOD) in PCR-based analyses of low concentration DNA. In particular, environmental DNA (eDNA) studies require sensitive and reliable methods to detect rare and cryptic species through shed genetic material in environmental samples. Current strategies for assessing detection limits of eDNA are either too stringent or subjec
Authors
Margaret Hunter, Robert M. Dorazio, John S. Butterfield, Gaia Meigs-Friend, Leo Nico, Jason A. Ferrante
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Evaluating the piscicide rotenone as an option for eradication of invasive Mozambique tilapia in a Hawaiian brackish-water wetland complex

Mozambique tilapia Oreochromis mossambicus were recently discovered in ‘Aimakapā Fishpond, a 12-hectare brackish-water wetland complex in Kaloko-Honokōhau National Historical Park, on the Island of Hawai’i. As a possible eradication method, we evaluated rotenone, a natural piscicide used in fish management and the active ingredient in plants traditionally used by indigenous Hawaiians for capturing
Authors
Leo Nico, Ronald A. Englund, Howard L. Jelks
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Genetic analysis of invasive Asian Black Carp (Mylopharyngodon piceus) in the Mississippi River Basin: evidence for multiple introductions

Invasive Asian Black Carp (Mylopharyngodon piceus) have been present in USA aquaculture facilities since the 1980s and wild Black Carp have been found in the Mississippi River Basin since the early 1990s. This study characterizes the genetic diversity and relatedness of the Basin’s Black Carp and clarifies the introduction history. Analyses focused on three mitochondrial markers (control region, c
Authors
Margaret E. Hunter, Leo G. Nico
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

One carp, two carp: are there more carp in the Wailoa River?

The February, 2015 issue of Hawaii Fishing News included the annual list of Hawai`i records for the largest fish of various species caught in the state. Among the new records was one for a 15-pound grass carp (Ctenopharyngodon idella) caught by Avery Berido in the Wailoa River at Hilo on September 13, 2013. A photograph taken by Mr. Berido of the record grass carp garnered our attention because pi
Authors
Bruce C Mundy, Leo Nico, Annette Tagawa
By
Ecosystems Mission Area, Wetland and Aquatic Research Center

Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States

In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 w
Authors
Rebecca A. Cole, Anindo Choudhury, Leo G. Nico, Kathryn M. Griffin
By
Ecosystems Mission Area, National Wildlife Health Center, Wetland and Aquatic Research Center

Non-USGS Publications**

Keevin, T.M., L.G. Nico, and D.C. Taphorn. 2015. Obituary: Jamie Edward Thomerson (1935-2015). Copeia 2015:1096-1101. (pdf available from author)
Nico, L.G. & S.J. Walsh. 2011. Nonindigenous freshwater fishes on tropical Pacific islands: a review of eradication efforts. Pages 97-107 in C. R. Veitch, M. N. Clout, and D. R. Towns, editors. Island Invasives: Eradication and Management. International Union for Conservation of Nature (IUCN), Gland, Switzerland and Centre for Biodiversity and Biosecurity (CBB), Auckland, New Zealand.
Nico, L.G., H.L. Jelks, & T. Tuten. 2009. Non-Native suckermouth armored catfishes in Florida: Description of nest burrows and burrow colonies with assessment of shoreline conditions. Aquatic Nuisance Species Research Bulletin 9: 1-30. [Link]
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O.M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2006. Lista de los peces identificados para la cuenca del río Ventuari. Apéndice 7) p 214- 223 in C.A. Lasso, J.C. Señaris, L.E. Alonsi, & A.L. Flores (editors). Rapid assessment of the biodiversity of the aquatic ecosystems of the Ventuari and its confluences with the Orinoco River, Amazonas State, Venezuela. RAP Bulletin of Biological Assessment 30. Conservation International, Washington, D.C.
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O.M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2006. Lasso-Alcalá, O., DoNascimiento C., & Milani, N.bPeces del bajo río Ventuari: Resultados del Proyecto de Investigación Biocentro-FLASA-Terra Parima (Capítulo 8), p 123-128. in: Lasso, C., Señarìs, J., Alonso, L., & Flores, A. (Editores). Evaluación Rápida de la Biodiversidad de los Ecosistemas Acuáticos en la Confluencia de los ríos Orinoco y Ventuari, Estado Amazonas (Venezuela). Boletín RAP de Evaluación Biológica 30. Conservation International. Washington DC.
Montaña, C.G., D.C. Taphorn, L.G. Nico, C.A. Lasso, O. León-Mata, A. Giraldo, O. M. Lasso-Alcalá, C. DoNascimiento, & N. Milani.2005. Fishes of the Ventuari River drainage, Amazonas State, Venezuela: 1) results of investigation; and 2) list of fish species. Pages 123-128 and 214-223, in C.A. Lasso, J.C. Señaris, L.E. Alonsi, and A.L. Flores, (editors). Rapid assessment of the biodiversity of the aquatic ecosystems of the Ventuari and its confluences with the Orinoco River, Amazonas State, Venezuela. RAP Bulletin of Biological Assessment, volume 30. Conservation International, Washington, D.C.
Fuller, P., L.G. Nico, & J.D. Williams. 1999. Nonindigenous fishes introduced to inland waters of the United States. American Fisheries Society Special Publication 27. American Fisheries Society, Special Publication 27, Bethesda, Maryland. 620 pp. [Link]
Nico, L.G., & J.E. Thomerson. 1989. Ecology, food habits and spatial interactions of Orinoco Basin annual killifish. Acta Biologica Venezuelica 12 (3-4): 106-120. (pdf available from Leo Nico)
Nico, L.G. 1989. Geographic distribution: Siren intermedia nettingi. SSAR Herpetological Review 20(1): 11.
Nico, L.G., & D.C. Taphorn. 1988. Food habits of piranhas in the low llanos of Venezuela. BioTropica 20(4): 311-321.
Nico, L.G., D.C. Taphorn & J.E. Thomerson. 1987. Limnological data on the habitat of annual fishes (Cyprinodontidae) in the Venezuelan Llanos with a key to fish identification. BioLlania 5: 129-144. (In Spanish.) (pdf available from author)
Nico, L.G., & D.C. Taphorn. 1986. Those bitin' fish from South America. Tropical Fish Hobbyist 34 (4): 24-27,30-34,36,40-41,56-57. (pdf available from author)
Nico, L.G., & D.C. Taphorn. 1985. Diet of Acestrorhynchus microlepis (Pisces: Characidae) in the low llanos of Venezuela. Copeia1985(3): 794-796.
Nico, L.G., & D.C. Taphorn. 1984. Biology of the tropical drum, Plagioscion squamosissimus, in the "Fernando Corrales" module of UNELLEZ, Apure State. Revista UNELLEZ de Ciencia y Tecnologia, No. 2, pp. 31-39. (In Spanish.)
Nico, L.G., & D.C. Taphorn. 1984. Limnology of Orinoco Basin annual killifish pools. Journal of the American Killifish Association, Technical Paper 24: 3-16.
Nico, L.G. 1983. Avian ecological investigation of the Horseshoe Lake Recreation Area. Southern Illinois University, Edwardsville. Final report submitted to Illinois Department of Conservation. i-iv + 80 p + 4 appendices. (pdf available from author)
Nico, L.G. 1981. Avian ecological investigation of Kaskaskia River Fish and Wildlife Area. Southern Illinois University, Edwardsville. Final report submitted to Illinois Department of Conservation. i-iii + 72 pp. (pdf available from author)

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

link
Live Asian carp on display in a U.S. food market

Survey and Assessment of Live Food Markets as an Invasion Pathway

Live food markets may be a source of the increasing number of non-native wild invertebrate and fish species, like Asian swamp eels and snakeheads. USGS is surveying such markets around the United States to identify and document species that might be of concern if released live into the wild to assess if the live food market is a possible invasion pathway.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Survey and Assessment of Live Food Markets as an Invasion Pathway

Live food markets may be a source of the increasing number of non-native wild invertebrate and fish species, like Asian swamp eels and snakeheads. USGS is surveying such markets around the United States to identify and document species that might be of concern if released live into the wild to assess if the live food market is a possible invasion pathway.
Learn More
link
USGS biologists sample fish and macroinvertebrates from Streams in Palau

Risk Analysis of Invasive Freshwater Fishes in Hawaii and Micronesia

Invasive species threaten biodiversity around the world, especially on islands. USGS scientists are helping to identify fish species that have the greatest potential to invade the fresh waters of Microneisa.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Risk Analysis of Invasive Freshwater Fishes in Hawaii and Micronesia

Invasive species threaten biodiversity around the world, especially on islands. USGS scientists are helping to identify fish species that have the greatest potential to invade the fresh waters of Microneisa.
Learn More
link
Parasites of Imported and Non-Native Wild Asian Swamp Eels

Parasites of Imported and Non-Native Wild Asian Swamp Eels

In parts of Asia, wild-caught and aquaculture-reared swamp eels are widely consumed as food by humans and are a common source of human gnathostomiasis, a food-borne zoonosis caused by parasitic nematodes of the genus Gnathostoma spp. In humans, the larvae of these nematodes can cause tissue damage and, in some instances, death. Over the past two decades, many thousands of Asian swamp eels have...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Parasites of Imported and Non-Native Wild Asian Swamp Eels

In parts of Asia, wild-caught and aquaculture-reared swamp eels are widely consumed as food by humans and are a common source of human gnathostomiasis, a food-borne zoonosis caused by parasitic nematodes of the genus Gnathostoma spp. In humans, the larvae of these nematodes can cause tissue damage and, in some instances, death. Over the past two decades, many thousands of Asian swamp eels have...
Learn More
link
Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on t

Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on the Island of Hawai’i

Mozambique tilapia, a highly invasive non-native fish of the family Cichlidae, were discovered in a wetland in Kaloko-Honokohau National Historical Park on the Big Island of Hawai'i. As the U.S. National Park Service works to restore the natural communities and functions of wetland ecosystems on the island, the eradication of the tilapia population is considered necessary to fully achieve wetland...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center
link

Development of an Environmental Assessment and Eradication Plan to Remove Tilapia from Ponds and Wetlands in National Parks on the Island of Hawai’i

Mozambique tilapia, a highly invasive non-native fish of the family Cichlidae, were discovered in a wetland in Kaloko-Honokohau National Historical Park on the Big Island of Hawai'i. As the U.S. National Park Service works to restore the natural communities and functions of wetland ecosystems on the island, the eradication of the tilapia population is considered necessary to fully achieve wetland...
Learn More
link
Black carp sample being preserved for genetic study

Genetic Analysis of Wild and Captive Black Carp in the Mississippi River Basin

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Wetland and Aquatic Research Center
link

Genetic Analysis of Wild and Captive Black Carp in the Mississippi River Basin

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.
Learn More

Variables pertaining to establishment success of non-native fishes introduced to the Hawaiian Islands and Guam for use in risk analysis modeling

Data represent dependent and independent variables used in logistic modeling for a study entitled "Evaluating Establishment Success of Non-native Fishes Introduced to Inland Aquatic Habitats of Tropical Pacific Islands." The phases of invasion of nonnative species are transport, introduction, establishment, and spread. To understand likelihood of establishment of species moved to new regions, inve
By
Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Occurrence of live Asian swamp eels in live food markets in USA derived from 2001-2018 surveys

The dataset consists of information on the occurrence of Asian swamp eels in live food markets. The data are from original surveys conducted by Leo G. Nico and colleagues. The surveys were conducted across the USA over the period 2001 to 2018. The dataset includes summary data on the numbers of markets surveyed each year, numbers and names of cities/metropolitan areas where surveys were conducted,
By
Biological Threats and Invasive Species Research Program, Wetland and Aquatic Research Center

Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions-Data

This dataset provides supporting information for the species distribution data used in the associated manuscript. Collections of five non-native fish species were made by a number of institutions, and several capture techniques were used. This dataset also includes number of individuals of each species captured at each locality.
By
Wetland and Aquatic Research Center
Image: Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Live Asian Swamp Eels Sold in a U.S. Market
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
Image: Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

Live Asian Swamp Eels Sold in a U.S. Market

These live Asian swamp eels were imported from southeast Asia and sold in an urban food market in the U.S. Raw or undercooked Asian swamp eels could transmit a parasitic infection called gnathostomiasis to consumers, and wild eels could become widespread in some U.S. waters.

By
Ecosystems, Communications and Publishing
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass Asian Swamp Eels: Predation on Juvenile Largemouth Bass
Asian Swamp Eels: Predation on Juvenile Largemouth Bass
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass Asian Swamp Eels: Predation on Juvenile Largemouth Bass
Asian Swamp Eels: Predation on Juvenile Largemouth Bass
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
video thumbnail: Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Asian Swamp Eels: Predation on Juvenile Largemouth Bass

Non-native or introduced populations of Asian Swamp Eels (family: Synbranchidae) exist in the wild in parts of Florida, Georgia, and Hawaii. This video shows predatory behavior of captive individuals.

By
Caribbean-Florida Water Science Center (CFWSC), Caribbean-Florida Water Science Center (CFWSC)
Was this page helpful?