BIOLOGY OF FIVE SPECIES OF SEAROBINS (PISCES, 

 TRIGLIDAE) FROM THE NORTHEASTERN GULF OF MEXICO 



Thomas C. Lewis and Ralph W. Yerger* 



ABSTRACT 



Geographically, Gulf populations oi Prionotus alatus appear to be restricted almost exclusively to 

 the eastern portion of the Gulf of Mexico, while Be//ator militaris, P. martis, P. roseus, and P. stearnsi 

 occur over the entire Gulf Bathymetrically, P. martis is a shallow shelf species; B. militaris and P. 

 roseus, middle shelf species; P. alatus, middle to deep shelf species; P. stearnsi, deep shelf species. 

 The size (standard length) of fi. militaris, P. alatus, P. martis, and P. roseus showed a significant 

 positive correlation with increasing depth of capture. Bellator militaris showed a significant "prefer- 

 ence" for fine sandy silt, clay, or mud bottoms. Prionotus stearnsi was captured in significantly 

 greater numbers during daytime trawling and is postulated to swim actively in the water column at 

 night. It appears to spawn from late summer to fall or early winter, while the remaining species spawn 

 from fall to spring or early summer. Adult P stearnsi differed in food habits by consistently consum- 

 ing relatively large fishes, while juveniles of this species and all the age groups of the other four 

 species fed consistently on crustaceans. 



Searobins of the family Triglidae are commonly 

 taken in shrimp trawls along the coast of the Gulf 

 of Mexico where they comprise an important ele- 

 ment of the benthic shelf ichthyofauna (Miles 

 1951; Hildebrand 1954; Springer and Bullis 1956; 

 Bullis and Thompson 1965; Roithmayr 1965; 

 Franks et al. 1972). They are not commercially 

 important in the Gulf of Mexico, but at least some 

 species are included among the bottomfishes 

 that are canned for pet food and reduced for fish 

 meal by commercial Gulf fisheries (Roithmayr 

 1965). Triglids also present a rich source of food 

 for the larger, commercially important fishes from 

 the Gulf Prionotus ophryas, P. roseus, and P. 

 stearnsi have been found in the stomachs of red 

 snapper, Lutjanus campechanus , taken off Pensa- 

 cola, Fla. (Jordan and Swain 1885; Jordan and 

 Evermann 1887). Prionotus roseus was reported 

 from the stomachs of red grouper, Epinephelus 

 morio, off Tampa, Fla. (Jordan and Evermann 

 1887). Hildebrand (1954) regarded P stearnsi as 

 one of the most important forage fishes in the 

 western Gulf where it was noted in the stomachs 

 of rock sea bass, Centropristis philadelphica; red 

 snapper; sand seatrout, Cynoscion arenarius; and 

 inshore lizardfish, Synodus foetens. 



Despite their importance as forage fishes, few or 

 no data are available on the biology of the Gulf 

 species, particularly on those found in deeper 



^Department of Biological Science, Florida State University, 

 Tallahassee, FL 32306. 



water. What little is known appears widely scat- 

 tered in the literature, usually in faunal lists. The 

 only in-depth studies on the biology of western 

 North Atlantic triglids (Marshall 1946; McEach- 

 ran and Davis 1970) are on the two species (Pri- 

 onotus carolinus and P. evolans) that do not occur 

 in the Gulf. 



Our study was undertaken to analyze the spe- 

 cies composition of the northeastern Gulf triglid 

 fauna on the continental shelf between 20 and 

 190 m, to determine the distribution and abun- 

 dance of this fauna, and to investigate aspects of 

 their biology. Thirteen species (Bellator brachy- 

 chir, B. egretta, B. militaris, Prionotus alatus, P. 

 martis, P. ophryas, P. paralatus, P. roseus, P. rubio, 

 P. salmonicolor, P. scitulus, P. stearnsi, P. tribulus) 

 were collected, but only five species (B. militaris, 

 P. alatus, P. martis, P. roseus, P. stearnsi) were 

 taken in sufficient numbers to report on their 

 biology 



MATERIALS AND METHODS 



Specimens were collected from July 1969 to 

 October 1971 aboard the RV Tursiops and the 

 USNS Lynch. Most cruises were conducted 

 aboard the Tursiops from October 1970 to Octo- 

 ber 1971 as part of the "Gulf Shelf Project" 

 conducted by the Edward Ball Marine Labora- 

 tory, Department of Oceanography, Florida State 

 University. Fishes were captured in a 16-foot 

 (4.9-m) try-net otter trawl with a %-inch (1.9-cm) 



Manuscript accepted August 1975. 

 FISHERY BULLETIN: VOL. 74, NO. 1, 1976. 



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