Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 11. The scalloped hammerhead sharkSphyrna lewini(Griffith and Smith)
- 1 December 2005
- journal article
- Published by National Inquiry Services Center (NISC) in African Journal of Marine Science
- Vol. 27 (3) , 517-528
- https://doi.org/10.2989/18142320509504112
Abstract
Between 1978 and 1998, a total of 3 385 scalloped hammerhead sharks Sphyrna lewini was caught in the protective nets off KwaZulu-Natal. The mean annual catch was 166 sharks (range 60–279). There was a significant decrease in catch rate with time, but the relationship with the population size in KwaZulu-Natal waters is unknown. Size and sex segregation is indicated. Sizes-at-50% maturity were 161.5cm (males) and 183.1cm (females). Most of the catch (91%) was immature, but neonates are poorly sampled by the 51-cm meshed nets. In small animals (<160cm precaudal length, PCL), males significantly outnumbered females by 2.2:1, and in large animals by 3.6:1. The length-mass relationship differed between sexes. Catches of both small and large animals were highest in summer. Most of the large males were caught in November and December, consistent with an inshore movement of mature animals to breed in summer, but no evidence of recent mating was observed in either sex. Females pregnant with term embryos (median emb...Keywords
This publication has 0 references indexed in Scilit: