Checklist of Gastropods from the Exclusive Economic Zone (EEZ), Sarawak, Malaysia

Abstract

This study provides the first marine gastropod checklist from the Sarawak Exclusive Economic Zone (EEZ). Gastropod samples were collected from selected stations in the Sarawak EEZ using an otter trawl net with a stretched mesh size of 38 mm at the cod end. The trawling operations were conducted more than 12 nautical miles from the coast, and the area was divided into three depth strata: I) 20–50 m, II) 50–100 m and III) 100–200 m. A total of 23 gastropod species were identified during the two-month sampling period from 16 August until 6 October 2015, representing 8 superfamilies, 15 families and 20 genera. Superfamily Tonnoidea was represented by 7 species, followed by Muricoidea (5 species), Cypraeoidea (4 species), and Buccinoidea and Conoidea (both with 2 species). Other superfamilies were represented by a single species. Only 3 species were obtained in 2 depth strata, namely Melo melo, Murex aduncospinosus and Tonna galea. In addition, 9, 13 and 4 species of gastropods were found in strata I, II and III, respectively. The information on gastropod distributions at different depth strata in the Sarawak EEZ could be useful in updating the Malaysian species diversity database.

Kajian ini menyediakan senarai gastropod marin yang pertama dari perairan Zon Ekonomi Eksklusif (ZEE) Sarawak. Sampel gastropod dikumpul dari stesen yang terpilih di ZEE Sarawak. Operasi menunda menggunakan pukat tunda dengan saiz regangan 38 mm pada penghujung pukat. Operasi menunda dijalankan di kawasan melebihi 12 batu nautika dari pesisir pantai dan kawasan stesen dibahagi kepada tiga strata kedalaman iaitu, I) 20–50 m, II) 50–100 m dan III) 100–200 m. Sebanyak 23 spesies gastropod telah dikenalpasti sepanjang dua bulan kajian yang bermula dari 16 Ogos hingga 6 Oktober 2015 di mana ia terdiri daripada 8 superfamili, 15 famili dan 20 genus. Superfamili Tonnidae diwakili 7 spesies, diikuti Muricoidea (5 spesies), Cypraeoidea (4 spesies), Buccinoidea dan Conoidea (2 spesies). Manakala lain-lain superfamili hanya diwakili satu spesies sahaja. Didapati hanya 3 spesies berada di 2 strata kedalaman iaitu Melo melo, Murex aduncospinosus dan Tonna galea. Selain daripada itu, didapati 9, 13 dan 4 spesies gastropod dijumpai masing-masing pada strata I, II dan III. Maklumat berkenaan taburan gastropod dengan perbezaan strata kedalaman di ZEE Sarawak sangat berguna dalam pengemaskinian pangkalan data diversiti spesies di Malaysia.