Exoskeleton

1. Introduction Lernaea infection is a major disease problem encountered in carp culture in the Indian subcontinent and has been reported from Indian major carps Catla (Catla catla), Rohu (Labeo rohita), Mrigal (Cirrhinus mrigala) , exotic carps silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and indigenous carps Labeo fimbriatus (Nandeesha et al., 1984, 1985; Tamuli and Shanbhouge, 1996; Zafar et al., 2001). The three Indian Major Carps viz., Catla, Rohu and…

The Permian Mass Extinction Introduction There are five major extinctions in history: the Late Devonian, the Ordovician-Silurian, the Permian-Triassic, the Triassic-Jurassic, and the Cretaceous-Tertiary. Known as the Big Five, these extinctions exceeded all others in size and destruction, each killing more than 60% of species from that period. Each one acted as a bottleneck, allowing the survival of only a fraction of the organisms that had been thriving before, from which evolution and life…