km west of Newport (lat. 44°38' N), between 335 

 and 400 m deep with a small Cobb midwater 

 trawl ( 10 m mouth opening) with an opening and 

 closing cod end (Pearcy et al. 1977). This female 

 fits the descriptions by Grey (1960, 1961, 1964) 

 and Mukhacheva (1972). Maximum diameter of 

 eggs in the ovary was 0.16 mm. Grey (1964) con- 

 sidered fish of this size to be mature. 



Gonostoma atlanticum is usually distributed in 

 warm water of the Atlantic, Pacific, and Indian 

 Oceans. It is found in the eastern and central 

 North Atlantic, and it has usually been recorded 

 from equatorial waters in the Pacific and Indian 

 Oceans. The northernmost previous record (lat. 

 34°18.6' N) for its occurrence in the Pacific Ocean 

 was that of Berry and Perkins (1966), who cap- 

 tured several individuals off southern California. 

 The temperature of the water in which the OSUO 

 specimen was captured was 5.37°-5.70° C. Backus 

 et al. (1965) reported the occurrence of G. atlan- 

 ticum in the Atlantic Ocean in waters of 10°-11°C. 



Aphanopus carbo was first reported from the 

 Pacific Ocean off Bodega Bay and Fort Bragg, 

 Calif., in 1969 (Fitch and Gotshall 1972). Peden 

 (1974) reported a specimen from off the Strait of 

 Juan de Fuca. Clarke and Wagner (1976) col- 

 lected larvae and juveniles off Hawaii. Five 

 specimens were taken off Oregon in 1976: OS 

 5381 (476 mm SL), about 29 km off Cape Meares, 

 at about 183 m; OS 6115 (639 mm SL), about 37 

 km off Florence, at about 146 m; OSUO 2352 

 (570 mm SL), 2353 (558 mm SL), 2354 (547 mm 

 SL), 120 km west of Newport, at about 400-480 m, 

 in an opening and closing net. 



Our specimens compared with those from 

 Madeira, had slightly smaller horizontal orbit, 

 slightly wider suborbital head width, and slightly 

 shorter anal spines. Otherwise the Atlantic and 

 Pacific Ocean specimens are very similar. 



Gas Bladder Anatomy in Aphanopus'carho 



Although Maul (1954) mentioned that on re- 

 trieval to the surface the gas bladder in A. carbo 

 expands greatly, causing the skin of the abdomen 

 to split, none of our specimens exhibited this 

 characteristic. ShepeF stated that none of the 

 specimens examined by him had their skin split, 

 but that the stomach in most specimens (all from 

 the Atlantic Ocean) were everted. Only one of our 



^L. I. Shepel, Fishery Reconnaissance, Murmansk, U.S.S.R.. 

 pers. commun. 15 November 1977. 



specimens had an everted stomach. These differ- 

 ences led us to examine the gas bladder and as- 

 sociated structures in A. carbo. 



Bone ( 1971) described the anatomy and histol- 

 ogy of the gas bladder of A. carbo. Tucker (1953) 

 briefly mentioned the ribs and provided partial 

 radiographs of the ribs and vertebral column in 

 A. carbo and A. schmidti. However, we found no 

 descriptions of the relationship of the bladder to 

 the vertebral column, ribs, kidneys, and coelom. 

 Our examination of A. carbo shows that the gas 

 bladder of this species, and the structures as- 

 sociated with it, has several unusual characteris- 

 tics. Little variation in anatomy was noted in our 

 specimens. 



The position of the gas bladder in A. carbo is 

 typical of that in most fishes; it is ventral to the 

 vertebral column and kidneys and dorsal to the 

 peritoneal (abdominal) cavity (i.e., retroperi- 

 toneal) (Figure 1). The anterior end of the gas 

 bladder is below the sixth vertebra. From it, two 

 minute extensions proceed anterolaterally at 45°, 

 but the size of the extensions did not allow us to 

 trace them forward more than a few millimeters. 

 Posteriorly, the gas bladder extends to a blunt 

 end between vertebrae 42 and 45, directly dorsal 

 or slightly anterior to the vent. Although the dor- 

 soposteriad portion of the peritoneal cavity nar- 

 rows and curves ventrally, the gas bladder con- 

 tinues to parallel the vertebral column except for 

 a slight dip near the posterior end. The region be- 

 tween the gas bladder and the peritoneal cavity is 

 filled with hypaxial muscle. The bladder is 

 slightly narrowed at its anterior and posterior 

 ends. It is oval in cross section and slightly small- 

 er than the diameter of vertebral centra in our 

 preserved specimens (Figure 1). 



The kidneys extend anteriorly from the region 

 dorsal to the vent to the posterior portion of the 

 skull. They are enlarged in the area above the 

 vent, and between the anterior of the gas bladder 

 and posterior of the skull, and lie ventrolateral to 

 the vertebral column and dorsolateral to the gas 

 bladder. They terminate in a urinary duct that 

 appears to empty into a urogenital sinus. 



The ventral ribs are intimately associated with 

 the gas bladder and kidneys. A pair of ventral 

 ribs is present on all trunk vertebrae, but those 

 anterior to the gas bladder are short and thin. 

 These ribs are difficult to find but may be seen 

 readily in radiographs. From immediately an- 

 terior to the gas bladder to about the ninth ver- 

 tebra the ribs become progressively longer and 



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