The geographic range extension of crowned jellyfish to the north-western Bay of Bengal.

Autor: Dash, Gyanaranjan, Behera, Pralaya Ranjan, Pradhan, Rajesh Kumar, Sen, Swatipriyanka, Ghosh, Shubhadeep, Saravanan, Raju, K. R., Sreenath
Zdroj: Journal of Coastal Conservation (Springer Science & Business Media B.V.); Aug2023, Vol. 27 Issue 4, p1-15, 15p
Abstrakt: Changes in the distribution of jellyfish are increasingly recognised as a signal of a state shift in pelagic ecosystems. Cepheid medusae are pelagic scyphozoans belonging to the family Cepheidae and are mostly represented by the species of crowned jellyfish of the genera Cephea and Netrostoma. They pose a hazard to coastal fisheries and coastal tourism. The present study documents the geographic range extension of the crowned jellyfish, Netrostoma coerulescens towards the northwestern Bay of Bengal. This forms the first report of this jellyfish from the northeast coast of India. The study also provides a detailed taxonomic description of the species. The species was identified by a combination of morphological features. These include the short, laterally compressed, distally bifurcated mouth arms with numerous short, spindle-shaped appendages, the presence of 6–7 round-edged velar lappets and two small, pointed rhopaliar lappets per octant, and a central dome that is completely decorated with about 8–25 warts/papillae. The study also postulates the reason behind the geographical range extension, mass swarming and the stranding phenomenon of this jellyfish in the northwestern Bay of Bengal. Since the species is a tropical jellyfish, climate change-induced ocean warming might have facilitated the geographical range extension of this warm-water-preferring jellyfish to the northern higher latitudes. Because swarms and beach strandings of this jellyfish were only observed during warmer months, it is reasonable to believe that higher temperature promote its strobilation and rapid population growth. The repeated beach stranding only during cyclonic stormy weather indicates that the species is highly vulnerable to hydrographic turbulence created by strong and sustained wind, high wave action and surface currents. Further study is required to corroborate our current knowledge about the intricate dynamics that govern the sudden emergence and disappearance of this enigmatic jellyfish. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index