Abstract. — Dolphinfishes are 

 highly prized commercial and rec- 

 reational species of worldwide dis- 

 tribution in tropical and subtropi- 

 cal seas, but the development and 

 distribution of their larvae are 

 poorly understood. Common dol- 

 phin eggs hatch in about 38 hours 

 at 25°C based on a predictive re- 

 lationship among egg diameter, 

 water temperature, and develop- 

 ment time. Morphometries are 

 generally greater in pompano dol- 

 phin than in common dolphin. 

 Pompano dolphin are deeper-bod- 

 ied and have a larger eye by 9 mm, 

 and a larger mouth and longer 

 pre-anal length by about 13 mm. 

 Differences in pigment along the 

 caudal peduncle and its finfold 

 separate common dolphin from 

 pompano dolphin <4. 0—4.5 mm SL; 

 common dolphin lack pigment in 

 these areas. Number of spines 

 along the outer shelf of the pre- 

 opercle also separate species al- 

 though preopercle spines are often 

 difficult to count on larvae not 

 cleared and stained; common dol- 

 phin have four spines along the 

 outer preopercular shelf and pom- 

 pano dolphin have five. Pigmented 

 pelvic fins and bands of pigment 

 laterally on both the body and me- 

 dian fins of common dolphin are 

 diagnostic for separating species 

 >8 mm SL; pompano dolphin lack 

 these characters. Both common 

 dolphin and pompano dolphin lar- 

 vae usually are found at >24°C, 

 >33 ppt, and beyond the 50 m 

 isobath. Preflexion larvae (<7.0- 

 7.5 mm SL) were primarily col- 

 lected in oceanic waters. Both spe- 

 cies may spawn year-round, at 

 least in the southern part of the 

 survey area. Larval common dol- 

 phin are significantly more abun- 

 dant than pompano dolphin. 



Larval development, distribution, 

 and abundance of common dolphin, 

 Coryphaena hippurus, and 

 pompano dolphin, C. equiselis 

 (family: Coryphaenidae), in the 

 northern Gulf of Mexico* 



James G. Ditty 

 Richard F. Shaw 



Coastal Fisheries Institute. Center for Coastal, Energy, and Environmental Resources 

 Louisiana State University, Baton Rouge, LA. 70803 



Churchill B. Grimes 



Southeast Fisheries Science Center, National Marine Fisheries Service, NOAA 

 Panama City Laboratory, 3500 Delwood Beach Road 

 Panama City, FL 32408 



Joseph S. Cope 



Coastal Fisheries Institute, Center for Coastal . Energy, and Environmental Resources 

 Louisiana State University, Baton Rouge, LA 70803 



The dolphinfishes, Coryphaena hip- 

 purus (common dolphin) and C. 

 equiselis (pompano dolphin), are 

 distributed worldwide in tropical 

 and subtropical seas (Briggs, 1960). 

 Highly prized as food, these fishes 

 are important recreational and 

 commercial species, but relatively 

 little is known about their early life 

 stages. Gibbs and Collette (1959) 

 reviewed spawning and adult sea- 

 sonal distribution for the western 

 North Atlantic Ocean, and Palko et 

 al. ( 1982) compiled dolphinfish bio- 

 logical data. Aoki and Ueyanagi 

 (1989) discussed larval and early 

 juvenile distribution for the eastern 

 Pacific, and similar information is 

 available for the western Pacific 

 and Indian oceans (Shcherbachev, 

 1973). Preliminary distribution 

 maps are available for the Gulf of 



Mexico (Gulf), but associated envi- 

 ronmental data are not included 

 (Richards et al., 1984; Kelley et al., 

 1986). Embryonic development is 

 described for common dolphin 

 (Mito, 1960; Hassler and Rainville, 

 1975; Hagood and Rothwell 1 ) and 

 osteological development for both 

 species (Potthoff, 1980), but de- 

 scriptive larval morphology is pri- 

 marily limited to sizes >13 mm SL 

 (Gibbs and Collette, 1959; Shcher- 

 bachev, 1973). Okiyama (1988) and 

 Aoki and Ueyanagi (1989) provide 

 information on developmental mor- 

 phology of Pacific specimens <13 

 mm SL, but their illustrations are 



1 Hagood, R. W., and G. N. Rothwell. 1979. 

 Sea Grant interim project report — 1979. 

 Aquaculture in tropical ocean — Cory- 

 phaena sp. Oceanic Inst., Makapuu Point, 

 Waimanalo, HI 96795. 



Manuscript accepted: 20 October 1993 

 Fishery Bulletin 92:275-291 (1994). 



Contribution No. LSU-CFI-92-5 of Louisiana State University Coastal Fisheries 

 Institute. 



275 



