Complementary Description and Range Extension of an Unusual Caligid Copepod Anchicaligus nautili (Willey, 1896) (Copepoda: Siphonostomatoida) Parasitizing the Endangered Deep-sea Cephalopod Nautilus pompilius Linnaeus, 1758 from the Indian Ocean

• Published in: Thalassas : revista de ciencias del mar 2021-10, Vol.37 (2), p.757-766
• Main Authors: Aneesh, Panakkool Thamban, Helna, Ameri Kottarathil, Prabhakaran, Meethal Parambath, Ravinesh, Raveendhiran, Kumar, Appukuttannair Biju
• Format: Article
• Language: English
• Subjects: Abdomen; Aquatic crustaceans; Biology; Bycatch; Coastal Sciences; Deep sea; Deep water; Earth and Environmental Science; Earth Sciences; Eggs; Females; Fish & Wildlife Biology & Management; Fisheries; Freshwater & Marine Ecology; Hydrobiology; Males; Marine & Freshwater Sciences; Marine molluscs; Museum collections; Museums; Nautilus pompilius; New records; Oceanography; Plankton; Range extension
• ISSN: 0212-5919; 2366-1674
• DOI: 10.1007/s41208-021-00331-2

The present study reports an unusual caligid copepod, Anchicaligus nautili  (Willey, 1896 ) infesting the deep-water chambered nautilus Nautilus pompilius  Linnaeus, 1758 from the Indian Ocean. Both male and female are redescribed and illustrated based on the materials recovered from the museum collection of the Department of Aquatic Biology & Fisheries, University of Kerala, collected in March, 1985 from the Andaman region of the Indian Ocean as a trawl bycatch. The species is characterised by the presence of a pair of large lenses (conspicillae) in the median eyes, postanal-protrusions and the displacement of the caudal rami. It appears to be the first record of the species from Indian waters.