«1778 Bony Fishes Suborder GOBIOIDEI ELEOTRIDAE Sleepers by E.O. Murdy, National Science Foundation, Virginia, USA and D.F. Hoese, Australian Museum, ...»
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1778 Bony Fishes
by E.O. Murdy, National Science Foundation, Virginia, USA and D.F. Hoese, Australian Museum, Sydney, Australia
D iagnostic characters: Small to medium-sized (most do not exceed 20 cm, although Gobiomorus from
this area may reach 60 cm). Typically, body stout; head short and broad; snout blunt; gill membranes broadly joined to isthmus. Teeth usually small, conical and in several rows in jaws. Six branchiostegal rays.
Two separate dorsal fins, first dorsal fin with 6 or 7 weak spines, second dorsal fin with 1 weak spine followed by 6 to 12 soft rays; second dorsal fin and anal fin relatively short-based; origin of anal fin just posterior to vertical with origin of second dorsal fin; terminal ray of second dorsal and anal fins divided to its base (but counted as a single element); anal fin with 1 weak spine followed by 6 to 12 soft rays; caudal fin broad and rounded, compris- ing 15 or 17 segmented rays; pectoral fin broad with 14 to 25 soft rays; pelvic fin long with 1 spine and 5 soft rays. Pelvic fins separate and not connected by a membrane. Scales large and either cycloid or ctenoid. No lateral line on body. Head typically scaled, scales being either cycloid or ctenoid with a series of sensory ca- nals and pores as well as cutaneous papillae. Colour: not brightly coloured, most are light or dark brown or olive with some metallic glints.
Habitat, biology, and fisheries: Typically occur in fresh or brackish waters, although some species are truly marine. Omnivorous. Bottom-dwelling fishes. Many are relatively inactive, hence the common name of sleeper. Found in all subtropical and tropical waters (except the Mediterranean and its tributaries). Comprises approximately 40 genera and 150 species; 5 genera and 10 species are recorded from this area. Of no com- mercial or recreational importance other than as food for larger fishes. Occasionally the larger species may be seen in local markets.
Perciformes: Gobioidei: Eleotridae 1779 Similar families occurring in the area Gobiidae: base of second dorsal fin much longer than distance from end of second dorsal fin to base of caudal fin; pelvic fins connected to form a disc in species from fresh and brackish water, separated only in species liv- ing on or around reefs. Size small; adults typically less than 10 cm in length.
Key to the species of Eleotridae occurring in the area Note: This key is exclusive of the dwarf fresh-water general Microphilypnus and Leptophilypnus. The taxonomy of species of Eleotris and Dormitator is unresolved and no key to species is available for these genera.
1a. Prominent, ventrally pointed spine on preopercle present, this spine may be difficult to see as it is is often covered by skin............................. ® 2 1b. Preopercular spine absent............................... ® 3 2a. Scales cycloid and smooth, about 90 longitudinal rows; caudal fin extending anteriorly onto body; body very slender, elongate, and terete, the depth contained 7 to 9 times in standard length (emerald sleeper)......................... Erotelis smaragdus 2b. Scales ctenoid and rough, 40 to 65 longitudinal rows; caudal fin not extending anteriorly on body; body depth moderate............................. Eleotris 3a. First dorsal fin with 6 spines; body with about 40 to 65 longitudinal scale rows; body and head strongly compressed (bigmouth sleeper)............... Gobiomorus dormitor 3b. First dorsal fin with 7 spines; body with fewer than 40 or more than 90 longitudinal scale rows; body deep.................................... ® 4
List of species occurring in the area Dormitator cubanus Ginsburg, 1953. To 10 cm. Fresh water, Cuba.
Dormitator lophocephalus Hoedeman, 1951. To 9 cm. Suriname.
Dormitator maculatus (Bloch, 1792). To 30 cm, common to 14.5 cm. Fresh and brackish waters, Chesapeake Bay to N Gulf of Mexico and SE Brazil.
Eleotris amblyopsis (Cope, 1871). To 8.3 cm. N and NE South America.
Eleotris belizanus Sauvage, 1880. To 10 cm. Belize, French Guiana.
Eleotris perniger (Cope, 1871). To 13 cm. St. Martin Island.
Eleotris pisonis (Gmelin, 1789). To 25 cm, common to 12.5 cm. Fresh and brackish waters, South Carolina, Bermuda, Bahamas, and N Gulf of Mexico to SE Brazil.
Erotelis smaragdus (Valenciennes in Cuvier and Valenciennes,, 1837). To 20 cm. Marine waters, SE Florida, Bahamas, and N Gulf of Mexico to Brazil.
Gobiomorus dormitor Lacepède 1800. To 60 cm, common to 36 cm. Fresh and brackish waters, S Florida and S Texas to E Brazil.
Guavina guavina (Valenciennes in Cuvier and Valenciennes, 1837). To 30 cm. Cuba, Puerto Rico, Mexico, Panama to Brazil.
References Birdsong, R.S. 1981. Review of the gobiid fish genus Microgobius. Bull. Mar. Sci., 31(2):267-306.
Birdsong, R.S. 1988. Robinsichthys arrowsmithensis, a new genus and species of deep-dwelling gobiid fish from the Western Caribbean. Proc. Biol. Soc. Wash., 101(2)1988:438-443.
Böhlke, 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. Philadelphia, 20(3):45-174.
Bussing, W.A. 1996. A new species of eleotridid, Eleotris tecta, from Pacific slope streams of tropical America (Pisces:
Eleotrididae). Revista de Biologia Tropical, 44(1):251-257.
Bussing, W.A. 1996. Sicydium adelum, a new species of gobiid fish (Pisces: Gobiidae) from Atlantic slope streams of Costa Rica. Revista de Biologia Tropical, 44(2):819-825.
Greenfield, D.W. 1988. A Review of the Lythrypnus mowbrayi Complex (Pisces: Gobiidae), with the Description of a New Species. Copeia, 1988(2):460-470.
Hoese, D.F. 1978. Families Gobiidae and Eleotridae. FAO Species Identification Sheets for Fishery Purposes: Western Central Atlantic (Fishing Area 31). Vols. 1-7, edited by W. Fischer. Rome, FAO (unpaginated).
Pezold, F. 1984. A revision of the gobioid fish genus Gobionellus. Unpubl. Ph.D. diss. Austin, University of Texas.
Pezold, F. 1993. Evidence for a Monophyletic Gobiinae. Copeia, 1993(3):634-643.
Robins, C.R., G.C. Ray, and J. Douglass. 1986. A Field Guide to Atlantic Coast Fishes of North America. Houghton Mifflin.
Smith, C.L. 1997. National Audobon Society Field Guide to Tropical Marine Fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda. Chanticleer Press, Inc., New York, 720 p.
Smith, D.S. and C.C. Baldwin. 1999. Psilotris amblyrhynchus, a new seven-spined goby (Teleostei: Gobiidae) from Belize, with notes on settlement-stage larvae. Proc. Biol. Soc. Washington, 112(2):433-442.
Watson, R.E. 1996. Revision of the subgenus Awaous (Conophorus) (Teleostei: Gobiidae). Ichth. Explor. Fresh., 7(1):1-18.
Perciformes: Gobioidei: Gobiidae 1781 GOBIIDAE Gobies by E.O. Murdy, National Science Foundation, Virginia, USA and D.F. Hoese, Australia Museum, Sydney, Australia D iagnostic characters: Typically very small (most do not exceed 10 cm), the smallest known vertebrate is a goby, Trimmatom nanus, that matures at 8 mm. The majority of gobies have united pelvic fins forming a ventral disc; those gobies with pelvic fins not united are typically found in coral reef areas.
Typically, but with many exceptions, body stout; head short and broad; snout rounded; the teeth are usually small, sharp, and conical and are found in 1 to several rows in the jaws; gill membranes broadly joined to isthmus. The head typically has a series of sensory canals and pores as well as cutaneous papillae. Two separate dorsal fins, first dorsal fin with 4 to 8 weak spines, second dorsal fin with 1 weak spine followed by 9 to 18 soft rays; caudal fin broad and rounded, comprising 16 or 17 segmented rays; anal fin with 1 weak spine followed by 9 to 18 soft rays; the terminal ray of the second dorsal and anal fins is divided to its base (but only counted as a single element); pelvic fin long with 1 spine and 5 rays, pelvic-fin spines usually joined by fleshy membrane (frenum), and innermost pelvic-fin rays usually joined by membrane, forming a disc; pectoral fin broad with 15 to 22 rays. The head is often scaled, scales being either cycloid or ctenoid.There is no lateral line on the body. Colour: highly variable. Coral reef species are typically brightly coloured; soft bottom and estuarine species are more drab.
Habitat, biology, and fisheries: The Gobiidae is the largest family of marine fishes and comprises more than 220 genera and 1 500 species. This highly successful family primarily inhabits shallow tropical and subtropical waters, but has invaded nearly all benthic habitats from fresh water to the shoreline to depths exceeding 500 m. They are usually secretive in their habits and can be found on a variety of substrata from mud to rubble, and coral reefs are particularly rich in goby species. Some gobies spend their entire lives in fresh water, others migrate back and forth between fresh and brackish water environments, or between marine and brackish waters. Members of the subfamily Sicydiinae inhabit the upper reaches of rivers, often at great altitudes, and migrate downstream to spawn; when spawning is complete, the fertilized eggs drift out with currents to develop at sea, and the adults return to their upstream habitat, often overcoming torrential stream flows. Some gobies associate with other organisms such as shrimps, sponges, soft corals, and other fishes. For a few species, symbiotic relationships with other organisms are a necessary part of the goby’s lifestyle. For instance, the cleaner gobies of the Caribbean (Elacatinus) feed on ectoparasites of other fishes whereas the Indo-Pacific gobies of the genera Amblyeleotris and Cryptocentrus share a burrow with a snapping shrimp (Alpheus). Typically, female gobies lay a small mass of eggs, each attached by an adhesive stalk to the underside of dead shells or other firm overhanging substrate. The eggs are guarded and tended by the male. The family is represented by more than 30 genera and approximately 125 species in this area. Most gobiids are of no commercial or recreational importance other than as food for larger fishes. Post-larval fry of Awaous and Sicydium are popular food items to native peoples throughout this region. Fry are collected in nets as they enter river and stream mouths during migrations from the sea to fresh water, usually during a full moon.
1782 Bony Fishes Similar families occurring in the area Eleotridae: base of second dorsal fin equal to or shorter than distance from end of second dorsal fin to base of caudal fin; pelvic fins always separate; found mostly in brackish or fresh water habitats, only 1 species occurs on coral reefs.
Tripterygiidae: 3 separate dorsal fins present, 2 with flexible spines and 1 with soft rays; cirri may be present on eye.
Blenniidae: body without scales; dorsal fin continuous, Eleotridae with fewer than 20 flexible spines and 12 or more soft rays; cirri may be present on eye and on nape.
Key to the subfamilies of Gobiidae occurring in the area 1a. Dorsal and anal fins connected to caudal fin, both dorsal fins united by membrane;
mud-burrowing, elongate gobies with pink to purple skin.............. Gobionellinae 1b. Dorsal and anal fins separated from caudal fin, both dorsal fins typically separate........ ® 2
3a. Paired anterior interorbital pores present..................... Gobionellinae 3b. Usually a single anterior interorbital pore present or head pores completely lacking. If 2 anterior interorbital pores present (only Gobiinae in Area 31 with paired anterior interorbital pores are Coryphopterus hyalinus, C. personatus, and C. lipernes), then pelvic frenum lacking and pelvic fins nearly separate; if head pores absent, then 1 or more of the following conditions also exist: chest, head, nape, and pectoral-fin base unscaled and/or barbels present on chin (although exceptions exist, head pores are typically absent only in a few, small, coral reef gobies).............................. Gobiinae Key to the species of Gobiinae occurring in the area 1a. First dorsal fin with 6 or fewer spines. (Evermannichthys typically has 6 or fewer spines in the first dorsal fin but 7-spined Evermannichthys have been reported)............. ® 2 1b. First dorsal fin with 7 or 8 spines............................ ® 30 2a. Second dorsal fin with more than 20 elements; pelvic fins separate, with 1 spine and 4 soft rays................................... (Ptereleotris) ® 3 2b. Second dorsal fin with fewer than 20 elements; pelvic fins either separate or connected by membrane, with 1 spine and 5 soft rays.......................... ® 4
5a. Body mostly without scales, only a few scales anterior to caudal fin or none; body very slender, body depth contained 7 to 9 times in standard length without caudal fin; second dorsal fin with 1 spine and 10 to 15 soft rays............... (Evermannichthys) ® 6 5b. Body completely scaled, scales reaching anteriorly at least to origin of first dorsal fin; body deep, the depth contained 4 to 7 times in standard length; second dorsal fin with 1 spine and 8 to 11 soft rays.................................. ® 9
7a. Four to 5 spines in first dorsal fin; row of scales along base of anal fin.. Evermannichthys metzelaari 7b. Six to 7 spines in first dorsal fin; no scales along base of anal fin... Evermannichthys spongicola
9a. Top of head scaled to behind eyes; gill openings broad, extending to below posterior preopercular margin; spines of pelvic fin not connected by a membrane...... Priolepis hipoliti 9b. Top of head without scales; gill openings narrow, equal to pectoral-fin bases; spines of pelvic fins connected by a membrane forming a cup-shaped disc......... (Lythrypnus) ® 10