A NEW GENUS AND SPECIES OF EELPOUT (PISCES, 

 ZOARCIDAE) FROM THE GULF OF MEXICO 1 



Hugh H. DeWitt 2 



ABSTRACT 



Exechodontes daidaleus n.gen. and n.sp., captured at lat. 27°01 'N, long. 84°55 'Wat a depth of 503 m in 

 the Gulf of Mexico, is described and figured. Its characteristics include the presence of pelvic fins, the 

 absence of scales, teeth on the vomer but not on the palatines, the absence of enlarged canine teeth, 

 teeth on the lateral margin of the dentary and directed outward, grooves behind the upper and lower 

 lips interrupted at the symphyses, the absence of cephalic lateral-line pores, and a greatly reduced 

 lateral line. The new genus appears to be most closely related to the Hadropareinae of the western 

 North Pacific. A key to the genera of the Hadropareinae, including Exechodontes, is given. 



During June of 1969 the Bureau of Commercial 

 Fisheries (now the National Marine Fisheries 

 Service) RV Oregon II was engaged in a survey of 

 shrimp abundance in relatively deep water (360- 

 900 m) in the eastern Gulf of Mexico. Among the 

 fishes captured is one small specimen of a zoarcid 

 which does not appear to belong in any of the 

 currently recognized genera of the family. More 

 surprising, it seems most similar to a group of 

 genera known only from the western North Pacific 

 Ocean. 



Exechodontes n.gen. 



Type-Species Exechodontes daidaleus n.sp. 



Diagnosis. — A zoarcid with pelvic fins and lacking 

 scales, with vomerine teeth (two in type-species), 

 but without palatine teeth. No enlarged canine 

 teeth although a few anterior teeth in upper jaw 

 somewhat enlarged; teeth of lower jaw small, in 

 two distinct rows, the outer on the lateral and 

 anterior edge of the dentary such that the teeth 

 are directed outward and are visible when the 

 mouth is closed. Grooves behind upper and lower 

 lips interrupted at symphyses; upper lips not 

 greatly broadened posteriorly. Pores of lateral- 

 line canals absent on head and body; lateral line of 

 body greatly reduced, only a few neuromasts visi- 

 ble close behind head and base of pectoral fin. 



■Contribution No. 96 from the Ira C. Darling Center for Re- 

 search, Teaching and Service, University of Maine at Orono, 

 Walpole, Maine. 



2 Department of Oceanography, University of Maine at Orono, 

 Ira C. Darling Center, Walpole, ME 04573. 



Manuscript accepted April 1977. 



FISHERY BULLETIN: VOL. 75, NO. 4, 1977. 



Head small and without prominent bulging cheek 

 musculature. Pelvic rays long, but only about dis- 

 tal one-fifth of their length bends to extend into 

 the visible fins, the proximal four-fifths lying hid- 

 den beneath skin of ventrum. Branchiostegal rays 

 six. Vertebrae with anterior and posterior halves 

 of equal size. 



Discussion. — Using various keys to the genera of 

 Zoarcidae (Soldatov and Lindberg 1930; Norman 

 1966; Lindberg and Krasyukova 1975), 

 Exechodontes falls into a group of three genera 

 known only from the western North Pacific Ocean: 

 Hadropareia Shmidt (1904) andBilabria Schmidt 

 ( 1936), both monotypic, and Davidijordania Popov 

 (1931) with five species. These three genera con- 

 stitute the subfamily Hadropareinae (Shmidt 

 1950), characterized by the absence of spines in 

 the posterior portion of the dorsal fin, the presence 

 of pelvic fins and the absence of crests on the chin 

 (Lindberg and Krasyukova 1975). Exechodontes 

 seems closest to Hadropareia in that it lacks scales 

 and palatine teeth. Hadropareia has, however, 

 distinct pores in the infraorbital lateral-line canal 

 (other pores have not been described or illus- 

 trated) and a few pores in the anterior portion of 

 the lateral line which extends posteriorly about 

 three-fourths the length of the body. In addition, 

 Hadropareia is described and figured as having 

 the cheek musculature enlarged such that each 

 cheek forms a prominent bulge (Soldatov and 

 Lindberg 1930). Davidijordania differs from 

 Exechodontes in having scales, palatine teeth and 

 the groove behind the upper lip complete across 

 the snout. Bilahria differs in having scales, pores 



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