Shark Records from Longline Fishing Programs in Hawai'i with Comments on Pacific Ocean Distributions

Abstract

This paper summarizes records from longline fishing programs conducted in Hawai'i between 1959 and 1980. Data from 11 species of sharks (173 individual sharks) are reported and compared with worldwide records. Although much of the data is nearly 30 yr old, the information was never fully utilized and represents the following important findings. The relationship between clasper length and total length (TL) for bluntnose sixgill shark, Hexanchus griseus (Bonnaterre), indicates that males mature at about 309 cm TL. High fecundity (114 pups) is reported for the prickly shark, Echinorhinus cookei Pietschmann. The smallest mature male E. cookei (183 cm TL) and the smallest pregnant (205 cm TL) bignose shark, Carcharhinus altimus (Springer), are recorded. New maximum depth of capture records for the blacktip shark, Carcharhinus Umbatus (Valenciennes), at 64 m, and for the smooth hammerhead shark, Sphyrna zygaena (L.), at 68 m, are also documented. Distributions of deep-sea sharks in Hawai'i appear to be associated with isothermic submergence, and the sharks remain below the thermocline (100-400 m) and in water temperatures of 9-12°C. Carcharhiniform sharks in Hawai'i range to greater depths than reported elsewhere; this appears to be correlated with the Tropics having warmer water temperatures (20-26°C), which extend down to 100-400 m in depth.