Apristurus brunneus, A. kampae, and Parmaturus xaniurus were caught by trawl and longline between Washington and southern California (48°N to 32°N latitude) from June 2001 through October 2004. In females, oviducal gland width increased with TL in all three species but remained within 4 to 6% of TL. Oocyte diameter increased with TL during reproductive development in all species, and continued to increase with size after reproductive maturity was reached. The weight-length relationships differed significantly among species but not between sexes of any species from the eastern North Pacific combined. Using logistic regression, it was determined that total length at 50% maturity (TL50) of A. brunneus males was 514 mm TL and all A. brunneus males were mature at 547 mm TL. Female A. brunneus reached TL50 at 501 mm TL and all female A. brunneus were mature at 581 mm TL. Apristurus kampae males and females reached TL50 at approximately 485 mm TL and 490 mm TL, respectively. Parmaturus xaniurus males reached TL50 at 444 mm TL and females at 501 mm TL. Gravid female A. brunneus were found in all months of the year, but gravid P. xaniurus were found primarily June through September. Adult A. kampae females were found only in July through November and there were gravid females in all these months. Based upon gonadosomatic indices, I G, these species may mate within a defined period of time (April through June); however, A. brunneus appear to reproduce throughout the year and P. xaniurus reproduce within a defined season (approximately July through September).
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
- Egg case
- Gonadosomatic index
- Weight-length regression