Umbra pygmaea
(eastern mudminnow)

Pictures

Picture	Title	Caption	Copyright
Title Adult Caption Umbra pygmaea (eastern mudminnow); adult. Copyright ©Fishes of North Carolina/http://www.ncfishes.com - CC BY-NC-SA 4.0	Adult	Umbra pygmaea (eastern mudminnow); adult.	©Fishes of North Carolina/http://www.ncfishes.com - CC BY-NC-SA 4.0
Title Adult Caption Umbra pygmaea (eastern mudminnow); adult. Copyright ©Fishes of North Carolina/http://www.ncfishes.com - CC BY-NC-SA 4.0	Adult	Umbra pygmaea (eastern mudminnow); adult.	©Fishes of North Carolina/http://www.ncfishes.com - CC BY-NC-SA 4.0

Identity

Preferred Scientific Name

• Umbra pygmaea (DeKay, 1842)

Preferred Common Name

• eastern mudminnow

Other Scientific Names

• Fundulus fuscus Ayres, 1843
• Leuciscus pygmaeus DeKay, 1842
• Melanura annulata Agassiz, 1853
• Umbra limi pygmaea DeKay, 1842

International Common Names

• English: striped mudminnow
• French: petit poisson chien; poisson chien; umbre pygmée
• Russian: karlikovaya evdoshka
• Chinese: ai yin yú

Local Common Names

• Belgium: Amerikaanse hondsvis
• Denmark: lille hundefisk
• Finland: pikkukoirakala
• Germany: Amerikanischer Hundsfisch; Kleiner Hundsfisch
• Netherlands: Amerikaanse hondsvis
• Romania: tiganus
• Sweden: dvärghundfisk

Summary of Invasiveness

U. pygmaea is a small bodied fish native to the Atlantic and Gulf slopes of the USA (Page and Burr, 1991). It was imported in the early 20^th century to Europe (France, Belgium, Germany and the Netherlands) for ornamental reasons and as food for imported North American salmonids (Verreycken et al., 2010). More recent introductions have occurred in Poland (Grabowska et al., 2010) and Denmark (Nielsen, 2012). The largest number of localities in Europe is in southeast Netherlands and northeast Belgium (Verreycken et al., 2010). In its introduced range, U. pygmaea reaches its highest abundances in lentic waters, especially moorland pools (Dederen et al., 1986), where it has little competition from other species (Verreycken et al., 2010). Aquaculture and other ponds are a major source of individuals in riverine populations (Verreycken et al., 2010). U. pygmaea demonstrates a great tolerance of poor habitat quality, such as low pH, temperature and oxygen saturation (Poll, 1949; Dederen et al., 1986). Negative impacts of U. pygmaea are generally described as low to medium (Verreycken et al., 2010; Froese and Pauly, 2014), especially in riverine systems, but it may be considered a high impact species in ditches with dense vegetation or in waters without other fish species (such as acid moorland pools) (Dederen et al., 1986).

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Chordata
•             Subphylum: Vertebrata
•                 Class: Actinopterygii
•                     Class: Umbra pygmaea
•                         Order: Esociformes
•                             Family: Umbridae
•                                 Genus: Umbra
•                                     Species: Umbra pygmaea

Notes on Taxonomy and Nomenclature

Umbra pygmaea was originally described by DeKay (1842) as Leuciscus pygmaeus. U. pygmaea is one of three members in the genus Umbra (family Umbridae); namely, two North American species, U. pygmaea (eastern mudminnow) and U. limi (central mudminnow), and one European species, U. krameri (European mudminnow) (Kottelat and Freyhof, 2007). Schmidt and Daniels (2006) designated neotypes for both U. pygmaea and U.limi, because the original descriptions (DeKay (1842) and Kirtland (1840), respectively) did not provide enough information to allow an identification of either species.

Description

U. pygmaea is a small bodied fish (15 cm TL) with a robust body cylindrical near the head and slightly compressed towards the tail. The snout is short, with the mandible slightly protruding beyond the tip of the upper jaw. All fins are rounded, dorsal fin inserted far at the back, just behind the pelvic fins. Pigmentation is yellowish green with 10-12 narrow lateral dark stripes. A prominent dark blotch is visible at the caudal base (Kottelat and Freyhof, 2007; Froese and Pauly, 2014).

Distribution

U. pygmaea is native to the Atlantic and Gulf slopes of the USA, from southeastern New York (including Long Island) to St. Johns River drainage in Florida and west to Aucilla River drainage in Florida and Georgia (Page and Burr, 1991). It was imported in the early 20th century to Europe for ornamental reasons and as food for imported North American salmonids. It now occurs in six European countries: France, Belgium, Germany, the Netherlands, Poland and Denmark (Verreycken et al., 2010).

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

U. pygmaea was imported from the USA in the late 19^th/early 20^th century to Europe (France, Belgium, Germany and The Netherlands) (Verreycken et al., 2010). It has more recently been introduced to Poland (Grabowska et al., 2010) and Denmark (Nielsen, 2012). Despite being introduced into Europe over 100 years ago, the distribution of U. pygmaea is still limited in most of the countries where it now occurs (with only one site in Denmark and less than 10 localities each in France and Poland). However, southeast Netherlands and northeast Belgium harbour U. pygmaea in many localities (more than 900). The spread in the non-native range seems to be very slow and is mainly human mediated (due to its use as live bait or aquarium fish, or escapes from aquaculture ponds infested with U. pygmaea) (Verreycken et al., 2010).

Introductions

Risk of Introduction

The risk of introduction from its native area seems very small, but unintentional introduction from infested aquaculture ponds to other ponds in its non-native range, as happened in the Marne region, France (Guidou and Keith, 2002), or escapes/drifts from ponds into riverine systems are still possible (Crombaghs et al., 2000; Verreycken et al., 2010). Intentional releases from aquaria (Grabowski et al., 2010) or use as live bait (Nielsen, 2012) cannot be excluded as potential sources of introduction (Verreycken et al., 2010).

Habitat

The typical habitat of U. pygmaea is lowland waters with little to no streamflow, such as backwaters, ponds and irrigation channels (Kottelat and Freyhof, 2007). In its introduced range, the highest abundances are reached in lentic waters such as floodplain waters and especially moorland pools (Dederen et al., 1986), where U. pygmaea has little competition from other species. Aquaculture and other ponds are a major source of individuals in riverine populations (Verreycken et al., 2010).

Habitat List

Biology and Ecology

Genetics

Haploid chromosome number is 11, diploid 22 (Froese and Pauly, 2014). Natural hybridization between U. pygmaea and U. limi in the Hudson River drainage (New York state) was documented by Schmidt and Daniels (2006).

Reproductive Biology

Age at maturity is 1.7 ± 0.3 yrs. The species is oviparous. Maximum fecundity is around 2000 ± 700 eggs. Spawning takes place in April and May at temperatures between 9 and 15°C. U. pymaea females build nests and guard them. The larvae remain in algal nests for about 6 days (Froese and Pauly, 2014; Kuehne and Olden, 2014).

Physiology and Phenology

U. pygmaea demonstrates great adaptability and tolerance of poor habitat quality, such as low pH, temperature and oxygen saturation (Poll, 1949; Dederen et al., 1986). Poll (1949) documented an incident where an U. pygmaea individual survived a whole night out of water. Extremely low pH-values (pH 3) were tolerated in an experimental setup without any mortality, and eggs and fry were observed in waters with a pH as low as 3.5 (Dederen et al., 1986). In natural environments, Dederen et al. (1986) found U. pygmaea in waters pH ranging from 3.5 to 8.1.

Longevity

Panek and Weiss (2012) found U. pygmaea up to 5 years old in the native range. In its introduced range fish up to 5.5 years were observed (Dederen et al., 1986).

Population Size and Density

Densities in lotic waters in Belgium ranged from 0.2 to 664.0 individuals per 100 m of continuous electrofishing, with the majority of the sampling sites (51.2%) containing between 1.0 and 10.0 individuals per 100 m (Verreycken et al., 2010). den Hartog and Wendelaar-Bonga (1990) reported densities of up to 20 kg/ha in moorland pools in the Netherlands. Densities may be even higher (up to 250 kg/ha) in otherwise fishless pools (Verreycken, personal observation).

Nutrition

U. pygmaea is a bottom-feeding generalist and mainly feeds on insect larvae, worms, molluscs and crustaceans. Panek and Weis (2013) found a broad diet consisting of 13-17 distinct prey classes. Although regarded as an invertivore, fish alevins (sac fry) are also eaten (Froese and Pauly, 2014). Cannibalism was documented by Panek and Weis (2013) during the summer season.

Natural Food Sources

Climate

Latitude/Altitude Ranges

Air Temperature

Water Tolerances

Natural enemies

Notes on Natural Enemies

Verreycken et al. (2010) found no significant correlation between the number of U. pygmaea and the numbers of fish predators (pike Esox lucius, pikeperch Sander lucioperca and perch Perca fluviatilis more than 20 cm) in a sample site in Flemish lotic water. However, for lentic waters, Dederen et al. (1986) reported an inverse relation between the abundance of U. pygmaea and the presence of predatory fish species. In its native range, Panek (1981) similarly found an inverse relation with the number of fish species present. Grebe (Podiceps cristatus) is a possible regulator mudminnow densities (den Hartog and Wendelaar-Bonga, 1990).

Means of Movement and Dispersal

Natural Dispersal

Natural dispersal seems very slow and densities in lotic waters are generally low (Verreycken et al., 2010).

Accidental Introduction

Escapes from earthen aquaculture and other ponds are a major source of Umbra specimens in riverine populations (Guidou and Keith, 2002; Verreycken et al., 2010). Belgian pisciculturists unintentionally spread U. pygmaea to several ponds in the Marne region (France) in the 1980s.

Intentional Introduction

Originally U. pygmaea was imported as food for North American salmonids in Europe. It was later also introduced from the USA as an ornamental species. The release of live bait by anglers in Denmark and the release of ornamental fish in Poland were reported to be the sources of introduction in those countries (Verreycken et al., 2010).

Pathway Causes

Pathway Vectors

Impact Summary

Environmental Impact

Impact on Biodiversity

Negative impacts on biodiversity are generally described as low to medium (Verreycken et al., 2010; Froese and Pauly, 2014), especially in riverine systems. U. pygmaea may be considered a high impact species in ditches with dense vegetation or in waters without other fish species (Dederen et al., 1986). In moorland pools U. pygmaea may even play an important role as a top predator (Dederen et al., 1986). Vooren (1972) reported heavy predation on (protected) amphibian larvae.

Risk and Impact Factors

• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Pioneering in disturbed areas
• Tolerant of shade
• Capable of securing and ingesting a wide range of food
• Gregarious

• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Highly likely to be transported internationally illegally
• Difficult to identify/detect as a commodity contaminant
• Difficult/costly to control

Uses

Economic Value

U. pymaea is sold in the aquarium trade (Froese and Pauly, 2014) and has been used as a laboratory animal to study the effects of chemical pollutants (Hooftman and Vink, 1981).

Social Benefit

U. pymaea has been suggested as possible control agents for Aedes mosquitoes in marshes and slow-moving vegetated streams in the USA (Slavin et al., 1977).

Environmental Services

In moorland marshes in its non-native range, it may be a primary food source for grebe and common kingfisher Alcedo atthis (Vooren, 1970; Dederen et al., 1986).

Uses List

Animal feed, fodder, forage

• Bait/attractant
• Fodder/animal feed

Environmental

• Biological control

General

• Laboratory use
• Pet/aquarium trade
• Research model
• Sport (hunting, shooting, fishing, racing)

Diagnosis

Genetic diagnosis can be performed. There are 10 barcode sequences available for U. pygmaea from BOLD and GenBank (Encyclopedia of Life, 2015).

Detection and Inspection

U. pymaea may be detected using conventional fish sampling methods (boat and backpack electrofishers, fyke nets, seines and minnow traps). Once captured, the species is easily identified in its native as well as non-native region because, save a few exceptions, there is no overlap in area with its close congeners U. limi (found in North America) and U. krameri (found in the Danube drainage, Europe). Analysis of meristics, morphometry and genetics can help, using the dichotomous keys such as Page and Burr (1991) or descriptions from Schmidt and Daniels (2006) and Kottelat and Freyhof (2007).

Similarities to Other Species/Conditions

U. pygmaea looks very similar to its close congeners U. limi (found in North America) and U. krameri (found in Europe).

Prevention and Control

Prevention

Prohibition of the sale of U. pygmaea in the aquarium trade could restrict the non-native area and prevent further spread. In addition, better control of fish stocking with fish from infested ponds could help prevent further introductions.

Eradication

Eradication in a closed system may be feasible using piscicides (such as rotenone), especially in ponds where U. pygmaea is the only fish species present. Physical removal, even after draining a pond, seems very difficult, if not impossible, given that this species can survive buried in mud. In open systems eradication would be even more problematic.

Physical/Mechanical Control

Physical control of closed water systems may be feasible by removing the majority of the fish by draining the water or by catching the fish with fykes and/or nets.

Biological Control

Grebe (Podiceps cristatus) is a possible regulator of Umbra densities (den Hartog and Wendelaar-Bonga, 1990). Pike (Esox lucius) and other fish predators may help to reduce U. pygmaea populations, as Dederen et al. (1986) reported an inverse relation between the abundance of U. pygmaea and the presence of predatory fish species.

Chemical Control

Chemical control in a closed system may be feasible using piscicides (such as rotenone), especially in ponds where U. pygmaea is the only fish species present.

Monitoring and Surveillance (incl. Remote Sensing)

Regular fish monitoring programmes (using electrofishing, fykes or seine nets) may detect U. pygmaea. In the near future, e-DNA may also be a sampling method.

Gaps in Knowledge/Research Needs

It is not clear whether the situation has changed since Verreycken et al. (2010) reported the distribution of U. pygmaea’s non-native range. International cooperation would be needed to gather the current distribution in the non-native range again. In addition, more work is needed to study the impacts of U. pygmaea in lotic and especially lentic waters (such as predation on amphibian larvae and aquatic invertebrates).

References

Crombaghs BHJM; Akkermans RW; Gubbels REMB; Hoogerwerf G, 2000. The distribution and ecology of fish in flowing waters in Limburg. 496 pp.

Declerck S; Louette G; Bie Tde; Meester Lde, 2002. Patterns of diet overlap between populations of non-indigenous and native fishes in shallow ponds. Journal of Fish Biology, 61(5):1182-1197.

Dederen LHT; Leuven RSEW; Wendelaar-Bonga SE; Oyen FGF, 1986. Biology of the acid-tolerant fish species Umbra pygmaea (DeKay, 1842). Journal of Fish Biology, 28:307-326.

Encyclopedia of Life, 2015. Encyclopedia of Life. www.eol.org

Froese R; Pauly D, 2014. FishBase. http://www.fishbase.org

Geiter O; Homma S; Kinzelbach R, 2002. Inventory and assessment of invasive species in Germany. (Bestandsaufnahme und Bewertung von Neozoen in Deutschland.) Texte des Umweltbundesamtes 2002 [Texts of the Federal Environmental Office in 2002]. 174+36+31+52 pp.

Grabowska J; Kotusz J; Witkowski A, 2010. Alien invasive fish species in Polish waters: an overview. Folia Zoologica, 59(1):73-85.

Guidou F; Keith P, 2002. Population status of Umbra pygmaea pygmy umbre (DeKay, 1842) in the department of Marne. (Etat des populations de l'umbre pygmée Umbra pygmaea (DeKay, 1842) dans le département de la Marne.) Bulletin Français de la Pêche et de la Pisciculture [Bulletin of French Fishing and Aquaculture], 365/366:549-552. doi:10.1051/kmae:2002051

Hartog Cden; Wendelaar-Bonga SE, 1990. Umbra pygmaea, an acid-tolerant fish. Naturwissenschaffen, 77:40-41.

Hoese HD, 1963. Salt tolerance of the eastern mudminnow Umbra pygmaea. Copeia, 1:165-166.

Hooftman RN; Vink GL, 1981. Cytogenetic effects of the eastern mudminnow, Umbra pygmaea, exposed to ethyl methanesulfonate, benzo[a]pyrene, and river water. In: Ecotoxicology and Environmental Safety, 5. 261-269.

Keith P; Allardi J, 2001. Atlas des poissons d'eau douce de France. ([English title not available]). Paris, France: Muséum national d'Histoire naturelle, 1-387. Patrimoines naturels Vol. 47.

Kottelat M; Freyhof J, 2007. Handbook of European Freshwater Fishes. Cornol, Switzerland: Publications Kottelat, 646 pp.

Kuehne LM; Olden JD, 2014. Ecology and conservation of mudminnow species worldwide. Fisheries, 39:341-351.

NatureServe, 2014. NatureServe Explorer Comprehensive Species Reports. Arlington, VA, USA: NatureServe. http://explorer.natureserve.org/servlet/NatureServe

Nielsen JG, 2012. Small dogfish Umbra pygmaea. (Lille hundefisk Umbra pygmaea.) In: Atlas over danske ferskvandsfisk [Atlas of Danish freshwater fish] [ed. by Carl, H. \Møller, P. R.]. Københavns Universitet: Statens Naturhistoriske Museum, 369-373.

Page LM; Burr BM, 1991. A field guide to freshwater fishes of North America north of Mexico. Boston, USA: Houghton Mifflin Company, 432 pp.

Panek FM, 1981. PhD thesis. Newark, New Jersey, USA: Rutgers University, 113 pp.

Panek FM; Weis JS, 2012. Age, growth, and reproduction of the eastern mudminnow (Umbra pygmaea) at the Great Swamp National Wildlife Refuge, New Jersey. Northeastern Naturalist, 19:217-228.

Panek FM; Weiss JS, 2013. Diet of the eastern mudminnow (Umbra pygmaea DeKay) from two geographically distinct populations within the North American native range. Northeastern Naturalist, 20:37-48.

Poll M, 1949. [English title unavailable]. (L'introduction en Belgique et l'acclimatation dans la nature d'un poisson américain supplémentaire Umbra pygmaea (DeKay).) Institut Royal des Sciences Naturelles Bulletin, 25:1-11.

Schmidt RE; Daniels RA, 2006. Hybridization in Umbridae in the Hudson River, New York, with designation of neotypes for Umbra limi and Umbra pygmaea. Zootaxa, 1113:1-20.

Slavin PT; Bradford E; Halpin R; McConnick D, 1977. The eastern mudminnow Umbra pygmaea (DeKay): a potential control agent of woodland pool Aedes spp. Mosquito News, 37:301.

Verreycken H; Anseeuw D; Thuyne Gvan; Quataert P; Belpaire C, 2007. The non-indigenous freshwater fishes of Flanders (Belgium): review, status and trends over the last decade. Journal of Fish Biology, 71(Suppl. D):160-172. http://www.blackwell-synergy.com/doi/abs/10.1111/j.1095-8649.2007.01679.x

Verreycken H; Geeraerts C; Duvivier C; Belpaire C, 2010. Present status of the North American Umbra pygmaea (DeKay, 1842) (eastern mudminnow) in Flanders (Belgium) and in Europe. Aquatic Invasions [Proceedings of the 16th International Conference on Aquatic Invasive Species, Montreal, Canada, 19-23 April 2009.], 5(1):83-96. http://www.aquaticinvasions.ru/2010/AI_2010_5_1_Verreycken_etal.pdf

Vooren C, 1971. Ecological aspects of the introduction of fish species into natural habitats in Europe, with special reference to the Netherlands. J. Fish Biol, 4:565-583.

Wolter C, 2009. Fish neozoa in the river Oder. http://www.igb-berlin.de/IGB-Publikationen/Wolter_2009_e_AEeng.pdf (accessed February 2015)

Wolter C; Röhr F, 2010. Distribution history of non-native freshwater fish species in Germany: how invasive are they? Journal of Applied Ichthyology [Alien species in aquaculture and fisheries. Proceedings of a conference Managing Alien Species for Sustainable Development of Aquaculture and Fisheries (MALIAF), University of Florence, Italy, 5-7 November 2008.], 26(s2):19-27. http://www.blackwell-synergy.com/loi/jai

Links to Websites

Organizations

Belgium: Research Institute for Nature and Forest (INBO), Kliniekstraat 25,, B-1070 Brussel, www.inbo.be

USA: US Geological Survey (USGS), 11649 Leetown Road,, Kearneysville, WV 25430, www.usgs.gov

Principal Source

Draft datasheet under review

Contributors

06/03/15 Original text by:

Hugo Verreycken, Research Institute for Nature and Forest (INBO), Belgium

Distribution Maps