219 



Notes on the biology of Cepha/urus cephalus 

 and Parmaturus xaniurus 

 (Chondrichthyes: Scyliorhinidae) from 

 the west coast of Baja California Sur, Mexico 



Eduardo F. Balart 



Division de Biologia Manna, Centra de Investigaciones Biologicas del Noroeste, S,C. 

 Apdo Postal 128, La Paz, B C S , Mexico 23000 

 E-mail address ebalarKa'cibnor mx 



Jeanette Gonzalez-Garcfa 

 Carlos Villavicencio-Garayzar 



Laboratono de Elasmobranquios, Universidad Autonoma de Baia California Sur 

 Apdo Postal 19-B, La Paz, B C S, Mexico 23000 



were dissected, the diameter of all 

 visible oocytes were recorded, and 

 embryos were removed. For the sub- 

 sequent analysis of C cephalus, pre- 

 viously published data were also 

 used. The length-weight relation- 

 ship was determined with STATIS- 

 TICA software (StatSoft, Inc., 1995) 

 by using the exponential function of 

 the form 



W^aTL'', 



as used by Cross ( 1988) for the file- 

 tail catshark. Length-weight rela- 

 tionships were compared between 

 males and females by using an 

 analysis of covariance. 



The head, or lollipop, shark (Cephal- 

 urus cephalus) and filetail catshark 

 (Parmaturus xaniurus) are found in 

 the eastern Pacific in waters rang- 

 ing from 245 to 828 m and from 91 to 

 1251 m depth, respectively (Castro, 

 1983). Little is known of their 

 biology because they are rarely 

 captured. Cephalurus cephalus is 

 a benthic catshark and has been 

 recorded from southern Califor- 

 nia, Gulf of California, the Revil- 

 lagigedo Archipelago, and off the 

 coasts of Peru and Chile (Kato et al., 

 1967; Melendez and Meneses, 1989; 

 Pequeho, 1989). Mathews and Ruiz 

 (1974) reported it from the upper 

 Gulf of California, Mexico, and 

 Castro- Aguirre (1981) gave basic 

 information about its morphology, 

 taxonomy, and ecology based on 11 

 specimens from this locale. 



Parmaturus xaniurus is distrib- 

 uted from central California to the 

 Gulf of Cahfornia (Castro, 1983). 

 Cross ( 1988) has described its gen- 

 eral biology and Lee ( 1969 ) reported 

 that, in the Santa Barbara basin, 

 it consumed myctophids. Cailliet' 

 concluded that juveniles were meso- 

 pelagic, adults demersal, and noted 

 that efforts to determine their age 

 have failed because of the absence 

 of annual rings on the vertebrae. 



The objective of this study was to 

 provide additional data on the biol- 

 ogy of C cephalus and P. xaniurus, 

 with information on length-weight 

 relationships, and notes on repro- 

 ductive biology, including the sizes 

 of oocytes and embryos, the sex ratio 

 of embryos, and clasper length, for 

 specimens from the west coast of 

 Baja California Sur, Mexico. 



Materials and methods 



Fish were sampled by bottom trawl- 

 ing with commercial shrimp nets 

 (20-m mouth, 30-mm mesh size) 

 during the oceanographic expedi- 

 tion EP9505 along the Pacific coast 

 of Baja California Sur, Mexico. 

 Trawls were made at depths of 

 50-280 m from the RV El Puma 

 during May 1995. On 5 May two 

 scyliorhinid species (C. cephalus 

 and P. xaniurus) were collected and 

 whole specimens were frozen. All 

 specimens were captured at the 

 following three stations: 26°01.9' 

 N, 113 26.9W (280 m); 25'59.6'N, 

 113 20.5 W (260 m); 26 00. 7N, 113° 

 18.3'W(230m). Bottom temperature 

 at the collection sites was 10.0°C. 

 Total weight (W, g), and total length 

 (TL, mm) were recorded. Females 



Results and discussion 



Seventy-five catsharks were ob- 

 tained: 51 P. xaniurus and 24 C. 

 cephalus. The latter species is 

 recorded for the first time along 

 the west coast of the Baja Cali- 

 fornia peninsula. At one station, 

 C. cephalus was captured together 

 with P. xaniurus. as reported by 

 Mathews and Ruiz (1974). Other 

 organisms collected at the three sta- 

 tions were the fishes Merluccius 

 angustimanus , Physiculus rastrel- 

 liger, Kathetostoma averruncus, Sy- 

 nodus lucioceps, Hippoglossina sto- 

 mata, and Lepophidium spp., and 

 the crustaceans Pleuroncodes pla- 

 nipes and Cancer johngarthii. 



Cephalurus cephalus 



Of the 24 specimens, 23 were fe- 

 male, with a range of 224 and 295 

 mm TL (.v=249 mm TL). The single 

 male specimen was 298 mm TL. 

 Previously reported maximum total 



' Cailliet, G. 1981. Ontogenetic changes 

 in the depth distribution and feeding 

 habits of two deep-dwelhng demersal 

 fishes of Cahfornia: sablefish and filetail 

 cat sharks. Paper presented at the sixty- 

 first annual meeting of the Am. Soc. Ich- 

 tyol. Herpetol. 



Manuscript accepted 17 August 1999. 

 Fish. Bull. 98:219-221 (2000). 



