Charleston, South Carolina (Lacepede 1800).
Etymology/Derivation of Scientific Name
Gobiosoma – Latin gobius or gobio, “goby” and Greek soma, “body”; bosc – patronymic for Louis Augustin Guillaume Bosc (1759-1828), French naturalist who visited America from 1796-1798 (Boschung and Mayden 2004).
Gobiosoma bosci Bohlke and Robins 1968:56.
Maximum size: To about 64 mm in length (Fritzche 1978).
Coloration: Ground color light tan to nearly black, usually brown; body with 9-10 vertical bars separated by narrow lighter interspaces, bars faint or indistinct in specimens with light or dark ground color; fins dusky (Boschung and Mayden 2004). Fritzche (1978) noted that coloration is highly variable: color in life greenish to dusky above, pale underneath, nape and sides with very narrow pale crossbars; pectoral fin mostly greenish; other fins blackish, but with caudal fin slightly lighter than dorsal fins; males generally darker than females.
Counts: Usually 13 (12-14) second dorsal fin rays; usually 11 (10-12) anal fin rays (Hubbs et al 1991); usually 17 or 18 pectoral fin rays (16-19); caudal fin rays 8 + 7; opercular pores 2; preopercular pores 3; 5 branchiostegal rays; vertebrae: precaudal 11, caudal 16 (Bohlke and Robins 1968; Fritzche 1978).
Body shape: Short and stout; body depth contained fewer than seven times in standard length (Hubbs et al 1991).
Mouth position: Terminal (Fritzche 1978).
External morphology: Pelvic length contained 1.6 to 2.0 times in distance from base of pelvic fin to origin of anal fin; body naked; upper pectoral fin rays joined to membrane; tongue indented but not notched (Hubbs et al 1991); caudal fin short, round, shorter than head; pelvic disc short; pectoral fins broad, shorter than head (Fritzche 1978).
Internal morphology: Teeth pointed, in bands on each jaw, with some of outer teeth enlarged (Fritzche 1978).
Distribution (Native and Introduced)
U.S. distribution: Coastal; ranges from Long Island Sound to Campeche, Mexico (Hubbs et al. 1991).
Texas distribution: Inhabits most of the bays and estuaries in the state (Hubbs et al 1991). Warren et al. (2000) listed the following drainage units for distribution of Gobiosoma bosc in the state (question mark following drainage unit represents “native with reservation” category): Sabine Lake (including minor coastal drainages west to Galveston Bay) (?), Galveston Bay (including minor coastal drainages west to mouth of Brazos River), Brazos River (?), Colorado River (?), San Antonio Bay (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River) (?), Nueces River. Non-native population exists in the Concho River (P. Bean, unpublished data), likely because of incidental introduction.
Abundance/Conservation status (Federal, State, NGO)
Populations in the southern United States are currently stable (Warren et al. 2000). Linam and Kleinsasser (1987) collected 2 specimens from Cow Bayou (Sabine River basin). Gunter (1950) reported collection of 1 specimen in a salt flat pond, in the Aransas National Wildlife Refuge, on the south Texas coast. Gelwick et al. (2001) reported collection of species in Mad Island Marsh Preserve near the intercoastal canal, in March. Although seldom abundant in individual collections, Gobiosoma bosc was the most widely distributed Gobiosoma in Mississippi (Dawson 1966).
Macrohabitat: In southern part of Texas, often found in the lower reaches of coastal streams (Hubbs et al 1991). Enters freshwater (Lindquist 1980). Abundant in muddy creeks and bays (Ross and Rhode 2004).
Mesohabitat: Seldom abundant, but widespread in low to moderate salinity (Lindquist 1980; Ross and Rhode 2004). At East Bay (Galveston Bay Estuary, Texas) species was most abundant in the fall and was associated with emergent vegetation; within nonvegetated areas, the highest mean densities of this species were found in marsh channels; in this study, highest mean densities of the species were strongly associated with low, shoreline marsh sites (Rozas and Zimmerman 2000). In the Galveston Bay system, Texas, Gobiosoma bosc was a dominant species within marsh vegetation, in the fall (Minello and Webb 1997). Species selected vegetated areas in a Spartina alterniflora marsh on Galveston Island, Texas (Zimmerman and Minello 1984). In North Carolina, commonly found on shallow, soft, and structured bottoms over a wide range of conditions in all estuaries; apparently prefers complex habitats, and occupies shells, burrows or debris detritus; Ross and Rhode (2004) reported that the species was common in low salinity grass beds, and was most abundant in spring collections. Collection of this species in North Carolina indicated that both young and adults dwell principally on the bottom (Hildebrand and Cable 1938). Within Mississippi Sound, species exhibited distinct preference for salinities below 22.3 ‰ and a size-salinity relationship was indicated wherein fish of medium standard length classes (11.5-22.0 mm) preferred low salinity (0.3-4.7 ‰) and smaller fish were most common at higher salinities (14.8-24.7 ‰; Dawson 1966). Dawson (1966) noted that species has reportedly been taken over a salinity range from 0.04-45 ‰; observed water temperatures ranged from 10.0-33.2°C. Gunter and Hildebrand (1951) reported dead specimens on the shore during a cold wave on the south Texas coast when air temperature of 20°F was recorded.
Spawning season: Late-April – October (Hildebrand and Cable 1938; Massman et al. 1963; Breder and Rosen 1966; Dawson 1966; Dahlberg and Conyers 1973). According to Dahlberg and Conyers (1973), spawning commences in the spring when water temperatures are 16-20°C and terminates in the fall or late summer.
Spawning location: In South Carolina estuaries, species utilizes inside of oyster shells as spawning substrate (Crabtree and Middaugh 1982); eggs laid and cemented at one end in empty, gaping oyster and clam shells (Breder and Rosen 1966). In Georgia, spawning occurs in oyster reefs; female lays adhesive eggs inside dead, gaping, hinged oyster shells in location where tidal current restricts siltation and stagnation at low tide (Dahlberg and Conyers 1973). In shallow water along the shore (Hildebrand and Cable 1938).
Reproductive strategy: Male guards and aggressively defends nest until eggs hatch and larvae becomes free-swimming; defensive display described as the dorsal fin and pelvic disc erected, mouth opened broadly, and body color darkened (Dahlberg and Conyers 1973). In laboratory observations, male observed to provide additional circulation for eggs masses by fanning them with slow undulations of caudal fin (Dahlberg and Conyers 1973). Groups of eggs present in nest at different developmental stages suggested that males guarding nests were polygamous (Dahlberg and Conyers 1973; Shenker et al. 1983).
Fecundity: Ovaries of females (27-35 mm SL) collected in Georgia contained from 701-1,382 eggs; egg diameters ranged from 0.112-0.720 mm; most nests contained 332-2,000 eggs, but three others had 3.933, 8,000, and over 9,000 eggs (Dahlberg and Conyers 1973). Egg with a bundle of adhesive eggs attached to the egg membrane serving to attach the egg to submerged objects; fertilized eggs 1.2-1.37 mm in length and 0.52-0.59 mm in diameter; hatching occurred in about 4 days at water temperature from 26-28°C (Hildebrand and Cable 1938). Unfertilized eggs spherical, yellow and opaque; fertilized eggs demersal (Fritzche 1978).
Age/size at maturation: Possibly mature by 1st summer (a few months after hatching), but unlikely to be reached until 2nd summer; smallest mature female 23 mm, usually 25-30 mm (Hildebrand and Cable 1938; Fritzche 1978). Dawson (1966) collected gravid fish as small as 14.5 mm in late August; specimens as large as 29.5 mm observed in June and July.
Migration: Larvae migrate upstream toward low salinity habitats (Shenker et al. 1983), but the mechanism and timing of colonizing downstream habitats are unknown (Ross and Rhode 2004); this data confirms larval movement patterns observed by Massman et al. (1963).
Longevity: Probably 4 years (Boschung and Mayden 2004).
Food habits: Diet consists primarily of annelids and small crustaceans; fish are also attracted to injured or dead oysters (Hoese and Hoese 1967; Boschung and Mayden 2004). In laboratory observations, males ate eggs of a different Gobiosoma species even while guarding their own nests (Dahlberg and Conyers 1973).
Growth: Young-of-the-year averaged 9.8 mm in July, and attained a mean length of 18 mm by the following April (about the end of their 1st year of life); by April of their 2nd year, I-class fish reached mean length of 26 mm; larger specimens presumed to be II-class fish; 51.6 mm specimen thought to represent an age of at least four years (Dawson 1966). Juveniles attained 18 mm by August of 1st year (Hildebrand and Cable 1938; Fritzche 1978)
Phylogeny and morphologically similar fishes
Subgenus Gobiosoma. In marine environments, Gobiosoma bosc often confused with the code goby (G. robustum), but the two species are easily separated by the absence in G. robustum of a segment of the lateral canal above the opercle (Bohlke and Robins 1968). Counts of right pectoral fin rays in G. robustum average 16.5 (15-17) and may be found useful in distinguishing this species from G. bosc, in which this count averages 18 (Dawson 1966).
See Hildebrand and Cable (1938) and Fritzche (1978) for description and illustrations of larval and juvenile fish.
Commercial or Environmental Importance
Marine (category) – species requiring seawater for survival; colonizer (origin) – species that will spontaneously invade new areas beyond the original ones (Contreras-Balderas et al. 2002).
Bohlke, J.E., and C.R. Robins. 1968. Western Atlantic seven-spined gobies, with descriptions of ten new species and a new genus, and comments on Pacific relatives. Proc. Acad. Nat. Sci. Phil. 120(1968):45-174.
Boschung, H.T., Jr., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington, D.C. 736 pp.
Breder, C.M., Jr., and D.E. Rosen. 1966. Modes of Reproduction in Fishes. T.F.H. Publications, Jersey City, New Jersey. 941 pp.
Contreras-Balderas, S., R.J. Edwards, M.D. Lozano-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 12:219-240.
Crabtree, R.E., and D.P. Middaugh. 1982. Oyster shell size and the selection of spawning sites by Chasmodes bosquianus, Hyleurochilus geminatus, Hypsoblennius ionthas (Pisces, Blenniidae) and Gobiosoma bosci (Pisces, Gobiidae) in two South Carolina estuaries. Estuaries 5(2):150-155.
Dahlberg, M.D., and J.C. Conyers. 1973. An ecological study of Gobiosoma bosci and G. ginsburgi (Pisces, Gobiidae) on the Georgia coast. U.S. Fish. Bull. 71(1):279-287.
Dawson,C.E. 1966. Studies on the gobies (Pisces: Gobiidae) of Mississippi Sound and adjacent waters. I. Gobiosoma. American Midland Naturalist 76(2):379-409.
Gelwick, F.P., S. Akin, A. Arrington, and K.O. Winemiller. 2001. Fish assemblage structure in relation to environmental variation in a Texas gulf coastal wetland. Estuaries 24(2):285-296.
Gunter, G. 1950. Distributions and abundance of fishes on the Aransas National Wildlife Refuge, with life history notes. Publ. Inst. Mar. Sci. Univ. Tex. 1(2):89-101.
Gunter, G., and H.H. Hildebrand. 1951. Destruction of fishes and other organisms on the south Texas coast by the cold wave of January 28-February 3, 1951. Ecology 32(4):731-736.
Hildebrand, S.F., and L.E. Cable. 1938. Further notes on the development and life history of some teleosts at Beaufort, N.C. U.S. Fish. Bull. 48:505-642.
Hoese, D.H, and D. Hoese. 1967. Studies on the feeding reaction in Gobiosoma bosci. Tulane Stud. Zool. 14(2):55-62.
Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement 43(4):1-56.
Fritzche, R.A. 1978. Development of Fishes of the Mid-Atlantic Bight: Volume V – Chaetodontidae through Ophidiidae. Fish and Wildlife Service, Solomons, Maryland. 340 pp.
Lacepede, B.G.E. 1800. Histoire Naturelle des Poissons, Volume II. 632 pp.
Linam, G.W., and L.J. Kleinsasser. 1987. Fisheries use attainability study for Cow Bayou (Segment 0511). River Studies Report No. 5. Texas Parks and Wildlife, Austin, Texas. 12 pp.
Lindquist, D.G. 1980. Gobiosoma bosc (Lacepede), Naked goby. p. 795. In: D. S. Lee, C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister & J. R. Stauffer, Jr. (eds.), Atlas of North American freshwater fishes, North Carolina State Museum of Natural History, Raleigh, 854 pp.
Massmann, W.H., J.J. Norcross, and E.B. Joseph. 1963. Distribution of larvae of the naked goby, Gobiosoma bosci, in the New York River. Chesapeake Science 4(3):120-125.
Minello, T.J., and J.W. Webb, Jr. 1997. Use of natural and created Spartina alterniflora salt marshes by fishery species and other aquatic fauna in Galveston Bay, Texas, USA. Marine Ecology Progress Series 151:165-179.
Ross, S.W., and F.C. Rhode. 2004. The gobioid fishes of North Carolina (Pisces: Gobioidei). Bulletin of Marine Science 74(2):287-323.
Rozas, L.P., and R.J. Zimmerman. 2000. Small-scale patterns of nekton use among marsh and adjacent shallow nonvegetated areas of the Galveston Bay Estuary, Texas (USA). Marine Ecology Progress Series 193:217-239.
Shenker, J.M., D.J. Hepner, P.E. Frere, L.E. Currence, and W.W. Wakefield. 1983. Upriver migration and abundance of naked goby (Gobiosoma bosci) larvae in the Patuxent River estuary, Maryland. Estuaries 6:36-42.
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.
Zimmerman, R.J., and T.J. Minello. 1984. Densities of Penaeus aztecus, Penaeus setiferus, and other natant macrofauna in a Texas salt marsh. Estuaries 7(4A):421-433.