Larvae of Crossorhombus valde-rostratus (Alcock) and C. azureus (Alcock) (Heterostomata: Pisces) collected during the International Indian Ocean Expedition and Naga Expedition
Abstract
Larvae of Crossorhombus valde-rostratus (Alcock) and C. azureus (Alcock) containing post-flexion stages ranging in size from 6.0 mm to 12.9 mm SL and 7.5 mm to 18.8 mm SL respectively were found in the zooplankton collected during the International Indian Ocean Expedition (IIOE) 1960-65) and Naga Expedition (1959-61). In the Indian Ocean the larvae of C. Valde-rostratus appear to prefer open ocean, found in the stratum sampled during day time as well as during SW monsoon period whereas C. azureus showed a decided liking to coastal or nearshore waters and occurred in the stratum mostly during night. However they also preferred SW monsoon season as the other species. Naga samples also showed identical preferences in so far as diel variation is considered but they, were mostly found in open ocean. A significant negative correlation was found between the distribution of C. valde-rostratus and the dissolved oxygen values indicating their tolerance to low oxygen concentrations
Collections
- Scholarly literature [8843]