FISHERY BULLETIN: VOL. 86, NO. 4 



water trawls; 83% of the individuals were collected 

 within 250 m of the bottom. Fifty-four A. brunneus 

 (99-380 mm TL, median = 177) were collected in 

 22 trawls and 23 P. xaniurm (1 10-229 mm TL, me- 

 dian = 175) were collected in 17 trawls. 



The occurrence of juveniles and adolescents of 

 both species in midwater collections suggests that 

 the water column, especially within 200-300 m of 

 the bottom, is their nursery area, and would explain 

 their conspicuous absence in benthic collections dur- 

 ing the present study. Caillief also concluded that 

 P. xaniums are mesopelagic as juveniles and demer- 

 sal as adults. 



Interestingly, 119 midwater trawls in the Santa 

 Cruz Basin, CA and near Rodriguez Seamount (most 

 bottom depths between 1,200 and 2,200 m) (UCSB 

 fn 3) captured no scyliorhinid sharks (the trawls 

 were taken concomitantly with trawls in the near- 

 by Santa Barbara Basin). Bottom depths >1,000 m 

 may be beyond the range of both species. The deep- 

 est recorded collection of A. brunneus off southern 

 California was 933 m (Roedel 1951); the deepest 

 recorded collection of P. xaniums was 687 m 

 (Springer 1979). The absence of both species in mid- 

 water trawls in the Santa Cruz Basin and near 

 Rodriguez Seamount would not be surprising if 

 juveniles do not travel far horizontally and adults 

 do not occur below 1,000 m. 



Size 



The largest A. brunneus collected during the pres- 

 ent study (625 mm TL male) was less than the max- 

 imum recorded size (680 mm TL; Compagno 1984). 

 The largest P. xaniurus (574 mm TL female) was 

 greater than the maximum recorded size (550 mm 

 TL; Compagno 1984). Weight-length relationships 

 of males and females of both species were similar. 

 It is not known if males and females that were the 

 same size were the same age. Attempts at deter- 

 mining the ages of P. xaniurus were unsuccessful 

 (Cailliet 1986^). 



Reproduction 



Like many scyliorhinid sharks, A. brunneus and 

 P. xaniurus exhibit single oviparity: one fertilized 



Cailliet, G. M. 1981. Ontogenetic changes in the depth distri- 

 bution and feeding habits of two deep-dwelling demersal fishes off 

 California: sablefish and filetail cat sharks. [Abstr.] Am. See. 

 Ichthyol. Herpetol. Sixty-first Annu. Meeting, Corvallis, OR. 



''G. M. Cailliet, Moss Landing Marine Laboratories, Moss Land- 

 ing, CA, pers. commun. July 1986. 



egg enters each oviduct and, after a short period, 

 is deposited in a tough egg case on the substrate 

 where it is anchored by tendrils (Nakaya 1975). Em- 

 bryonic development takes place largely outside the 

 mother and may require a year to produce a hatch- 

 ling (Compagno 1984). 



Size at sexual maturity estimated during the pres- 

 ent study agrees with published observations for 

 both species (Jones and Geen 1977; Compagno 

 1984). Male P. xaniurus matured at a smaller size 

 than male A. brunneus. Females of both species 

 matured at about the same size and fecundity in- 

 creased with female size. Fecundity was greater 

 among A. brunneus as was the proportion of mature 

 females carrying egg cases, but the proportion of 

 body weight devoted to gonads and maximum 

 oocyte size were greater among P. xaniurus. 



Seasonal changes in gonadal development were 

 not well defined for either species; individuals in 

 both populations may be sexually active at any time 

 of the year. Several observations suggest that 

 oocyte production was seasonal: the highest propor- 

 tion of adult females with oocytes <10 mm in diam- 

 eter and the highest frequency of atretic oocytes 

 were observed from summer through fall when GSI 

 was lowest. 



There are few published observations on reproduc- 

 tive cycles of scyliorhinid sharks. Scyliorhinus 

 canicula, an abundant shelf and upper slope cat- 

 shark in the northeastern Atlantic Ocean, lays eggs 

 throughout the year. Seasonal maxima in egg cap- 

 sule production are apparent, but timing varies with 

 latitude. Size at sexual maturity also varies with 

 latitude; fish mature at a larger size at higher 

 latitudes (Ford 1921; Capape 1977). The fecundity 

 of female S. canicula (46-50 cm TL) ranges from 

 23 to 34 eggs; fecundity increases with fish size. 

 Eggs are 16 mm in diameter at ovulation. Annual 

 fecundity is about 96-115 eggs. In the Mediterra- 

 nean Sea, egg capsule incubation times range from 

 180 days for eggs deposited during the summer to 

 285 days for eggs deposited during the winter 

 (Capape 1977). 



Food Habits 



Apristurus brunneus and Parmaturus xaniurus 

 consumed, in order of importance, crustaceans, tele- 

 osts, and squids. Similar diets were reported for 

 both species by Jones and Geen (1977), Cailliet 

 (1981, see fn. 4), and Compagno (1984). The diets 

 of the two catsharks were broadly similar except for 

 the occurrence of crustaceans. Reptantian decapods 



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