Awaous banana

river goby

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Type Locality

Saint-Domingue (Valenciennes 1837).

Etymology/Derivation of Scientific Name

Banana – derived from the local vernacular, “banane”, in the Dominican Republic (Valenciennes 1837; Watson 1996).

Synonymy

Awaous banana was recognized as a distinct species (from A. tajasica) by Watson (1996).

Gobius (Awaous) banana Valenciennes 1837:103.

Gobius (Awaous) martinicus

Chonophorus bucculentus

Chonophorus contractus

Gobius mexicanus

Gobius transandeanus

Gobius dolichocephalus

Awaous nelsoni

Gobius (Awaous) guentheri

Awaous tajasica Edwards et al. (1986).

Awaous banana Nelson et al. 2004:169, 245-246; Hubbs et al. 2008:57.

Characters

Maximum size: 300 mm SL (Debrot 2003).

Coloration: Watson (1996) described life colors of both males and females: males are olive green above, ventrally golden yellow to orange; lower edge of upper lip and lower edge of opercle yellowish orange; pectoral fin yellowish; dorsal and caudal fins yellowish olive. Females are olive above, some golden markings along dorsum, ventrally white; pectoral fin with some lower rays white; anal fin translucent on basal half, dusky on distal half with reddish rays, margin white, anal spine white. See Watson (1996) for description of color in preservation; sexual dichromatism not evident in preservation. Edwards et al. (1986) described the two specimens taken in the Rio Grande (Texas): pale tan bodies with 7 to 8 dark blotches above the midline (blotches extended to the dorsum, and the last three blotches formed bars on the dorsal surface when viewed from above); venters white; caudal fins with 4 to 6 dark bands; dorsal fins with similar bands and coloration; anal fins white.

Counts: More than 70 scale rows in lateral series; second dorsal fin rays 11-12; 11-13 anal fin rays (Hubbs et al. 2008). Watson (1996) states that pore F, in adults, usually branched on each side with 2 openings; in small specimens (25-30 mm SL) pore F may be in various degrees of development, ranging from a small singular pore, an oblong or oval shaped pore to 2 pores in various degrees of separation. Edwards et al. (1986) described two specimens taken in the Rio Grande (Texas): numerous small teeth, 6 dorsal spines, 11 dorsal rays, 11 anal rays; the larger individual (97.7 mm SL) with 78 scales in the lateral series and 24 scales between origin of the dorsal and anal fins; the smaller individual (85.0 mm SL) with 80 scales in the lateral series and 22 scales between the origin of the dorsal and anal fins.

Mouth position: Mouth large and thick with upper lip extending well beyond the lower (Gilmore 1992).

Body shape: Short and stout body; body depth goes fewer than 7 times in standard length (Ross and Rhode 2004; Hubbs et al. 2008). Large males (usually over 160 mm SL) with head broadened and dorsoventrally depressed, upper jaw and unpaired fins increase in length (Watson 1996). Edwards et al. (1986) described two specimens taken in the Rio Grande (Texas): maximum depth of the larger individual (97.7 mm SL) was 17.3% of standard length and head length was 26.9% of standard length; maximum depth of the smaller individual (85.0 mm SL) was 16.4% of standard length and head length was 29.3% of standard length.

External morphology: Scales small; body mostly scaled; upper pectoral fin rays joined to membrane (Ross and Rhode 2004; Hubbs et al. 2008). Shoulder (under gill cover) with 2-3 distinct fleshy lobes; dorsal fins separated; pelvic fins completely united to form a round sucking disc (Ross and Rhode 2004).

Internal morphology: Tongue indented but not notched (Ross and Rhode 2004; Hubbs et al. 2008). In large males (usually over 160 mm SL) number of teeth in upper and lower jaws increase (Watson 1996).

Distribution (Native and Introduced)

U.S. distribution: Occurs from the Atlantic and Gulf coasts of the United States south through the West Indies and Central America to Venezuela and from northwest Mexico to northern Peru (Hubbs et al. 2008).

Texas distribution: Known only from the Rio Grange in Hidalgo and Cameron Counties (Edwards et al. 1986; Hubbs et al. 2008).

Abundance/Conservation status (Federal, State, NGO)

State Threatened (Texas; Hubbs et al. 2008). Vulnerable (Warren et al. 2000) in the southern United States. Threatened, US (American Fisheries Society status by Distinct Populations Segments; Musick et al. 2000). In the U.S., species mainly restricted to freshwater tributaries of Indian River Lagoon, Florida; extensive release of water from Lake Okeechobee into St. Lucie River by USACE and the SFWMD has changed salinity regimes, increased fish disease, created toxic dinoflagellate blooms, caused extensive fish mortality, and eradicated important nursery grounds; also toxic chemical spills in this area (Musick et al. 2000). Gilmore (1992) recommended species for “Threatened” status in Florida.

Habitat Associations

Macrohabitat: Freshwater/Estuarine (Hubbs et al. 2008). Amphidromous, marine to freshwater, tropical (Musick et al. 2000). Associated with rivers and streams (Watson 1996; Ross and Rhode 2004; Hulsman et al. 2008).

Mesohabitat: Usually reported from clear streams and rivers over sand and gravel; has been collected from turbid waters with muddy bottoms; usually encountered in fresh waters; occasionally taken in brackish conditions; species prefers clear flowing, oxygenated streams; sometimes found considerable distances upstream (Watson 1996). According to R.E. Watson (pers. comm. in: Gilmore 1992) the close dependence of this species on flowing water is a direct result of the peculiar modification of the gills, in which the outer surfaces are covered with sensory papillae, which apparently results in attendant loss of respiratory function. Adults are intolerant of salt water; however larvae do occur in marine and brackish water (R.E. Watson, pers. comm., August 2002 in: Nelson et al. 2004); adults occur in fresh water, larvae pelagic (Debrot 2003). In Indian River lagoon (Florida), specimens were collected from tributary streams, most often over a sand substrate at salinities of 0.0-4.0 ppt and at temperatures of 20-28°; majority of specimens were found below bridges which may indicate a preference for shaded areas of the stream and/or sediment deposited around bridge pilings (Gilmore and Hastings 1983; Gilmore 1992). Species mostly restricted to shallow estuarine habitats, rare in tidal freshwater (Ross and Rhode 2004). Colonizer of low salinity habitat (lower Rio Grande/Rio Bravo; Contreras-Balderas et al. 2002). In the mainstream of the Rio Grande (Texas) two specimens collected from a pool lined with slab-sided boulders; water temperature was 14°C; water flow was moderate to swift; little detritus, sand, or other fine substrates were present in area of capture (Edwards et al. 1986).

Biology

Spawning season:

Spawning habitat: Spawning occurs in fresh water with the eggs presumably drifting downstream, where they either hatch in brackish or salt water or do so before reaching there (Gilmore 1992; pers. comm., R.E. Watson in: Gilmore 1992).

Spawning behavior:

Fecundity: Eggs are small and number from 2,400-3,000 in large females (Gilmore 1992; pers. comm., R.E. Watson in: Gilmore 1992).

Age at maturation: 

Migration: Eggs are released in fresh water and drift downstream where they may reach brackish or salt water before hatching; most larvae probably reenter the parental stream, but some may be dispersed via ocean currents before returning to freshwater (Gilmore 1992; pers. comm., R.E. Watson in: Gilmore 1992).

Growth and Population structure: 

Longevity:

Food habits: Feeds heavily on filamentous algae, but will ingest sand consuming detrital and algal matter associated with it; feeds on animal matter only when other food items are unavailable (Watson 1996). Adult consume mostly algae (Debrot 2003).

Phylogeny and morphologically similar fishes

Host Records

Commercial or Environmental Importance

References

Contreras-Balderas, S., R. J. Edwards, M.D. Loranzo-Vilano, and M.E. Garcia-Ramirez. 2002. Fish biodiversity changes in the Lower Rio Grande/Rio Bravo, 1953-1996 - a review. Reviews in Fish Biology and Fisheries 12(2):219-240.

Debrot, A.O. 2003. A review of the freshwater fishes of Curacao, with comments on

those of Aruba and Bonaire. Carribean Journal of Science 39(1):100-108.

Edwards, R.J., T.S. Sturdivant, and C.S. Linskey. 1986. The river goby, Awaous tajasica (Osteichthyes: Gobiidae), confirmed from the lower Rio Grande, Texas and Mexico. Texas Journal of Science 38:191-192.

Gilmore, RG. 1992. River Goby, Awaous tajasica. pp 112-117 in: Gilbert, C.R. (ed.). Rare and Endangered Biota of Florida, Volume 2, Fishes. University Press of Florida, Gainsville.

Gilmore, R.G., and P.A. Hastings. 1983. Observations on the ecology and distribution of certain tropical peripheral fishes in Florida. Fla. Sci. 46(1):31-51.

Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2^nd edition 43(4):1-87.

Hulsman, H., R. Vonk, M. Aliabadian, A.O. Debrot, and V. Nijman. 2008. Effect of introduced species and habitat alteration on the occurrence and distribution of euryhaline fishes in fresh- and brackish-water habitats on Aruba, Bonaire, and Curacao (South Carribean). Contributions to Zoology 77(1):45-52.

Musick, J.A., M.M. Harbin, S.A. Berkeley, G.H. Burgess, A.M. Eklund, L. Findley, R.G. Gilmore, J.T. Golden, D.S. Ha, G.R. Huntsman, J.C. McGovern, S.J. Parker, S.G. Poss, E.Sala, T.W. Schmidt, G.R. Sedberry, H. Weeks, and S.G. Wright. 2000. Marine, estuarine, and diadromous fish stocks at risk of extinction in North America (exclusive of Pacific salmonids). Fisheries 25(11):1-30.

Nelson, J.S., E.J. Crossman, H. Espinoza-Perez, L.T. Findley, C.R. Gilbert, R.N. Lea, and J.D. Williams. 2004. Common and Scientific Names of Fishes from the United States, Canada, and Mexico. American Fisheries Society, Special Publication 29, Bethesda, Maryland. 386 pp.

Ross, S.W., and F.C. Rhode. 2004. The gobioid fishes of North Carolina (Pisces: Gobioidei). Bulletin of Marine Science 74(2):287-323.

Valenciennes, A. 1837. Tome douzieme. In: G. Cuvier and V. Valenciennes, Histoire naturelles des poisons. Levrault, Strasborg. 507 pp.

Warren, M.L., Jr., B.M. Burr, S.J. Walsh, H.L. Bart, Jr., R.C. Cashner, D.A. Etnier, B.J. Freeman, B.R. Kuhajda, R.L. Mayden, H.W. Robison, S.T. Ross, and W.C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.

Watson, R.E. 1996. Revision of the subgenus Awaous (Chonophorus) (Teleostei: Gobiidae). Ichthyol. Explor. Freshwat. 7(1):1-18.