Journal of the Marine Biological Association of India

Biological and fishery aspects of the devil rays; a case study from Negombo fish harbour, Sri Lanka

Volume 64 Issue 2

H. A. C. C. Perera and L. M. R. Lakpriya

10.6024/jmbai.2022.64.2.2280-15

Abstract

Devil rays are large, zooplankton feeding elasmobranchs in the ocean, which are globally threatened due to the high level of exploitation. There are seven species of devil rays in the world. Of this, five species are found in the Indian Ocean. There is a growing demand for their gill plates, flesh and cartilage, which are used as soup fillers in the Asian region. This growing demand is leading to the risk of the devil ray stocks declining. Therefore, devil rays are categorized as Appendix II species under CITES and Appendix I and II of CMS. A study on Mobula ray fishery and some aspects of their biology in Sri Lankan marine waters was conducted at Negombo, one of the major fish landing centres, from April to November 2019. The results showed that the highest juvenile percentage was represented by Mobula japanica (48%). The highest sub-adult and the adult percentage were recorded for M. tarapacana (52%) and M. kuhlii (52%) catches, respectively. The observed minimum and maximum disc widths of the devil rays showed a declining trend. Most of the devil rays were entangled in gillnet (66%) rather than longline, most were entangled in gillnet of mesh size 13.6 to 16.0 cm. The present study provides baseline information on devil ray species which will be helpful for policymakers to implement regulation and conservation management in the devil ray fishery.

Keywords

Devil rays, elasmobranches, management, threatened

Date : 24-08-2022