Penelitian ini bertujuan untuk mengetahui keanekaragaman spesies Bivalvia serta karakter morfologi eksternal, morfologi internal, dan habitat masing-masing jenis kerang yang terdapat di perairan pantai Sidoarjo. Penelitian dilakukan dalam dua tahap, yaitu penelitian di perairan Pantai Sidoarjo dan di laboratorium. Penelitian di lapangan dilakukan untuk koleksi spesimen bivalvia dan karakterisasi habitat, meliputi pengambilan sampel untuk pengukuran suhu, salinitas, pH air dan substrat, kekeruhan air serta tekstur substrat. Penelitian di lapangan dilakukan di 5 stasiun, setiap stasiun terdiri atas 3 garis transek dan masing-masing transek terdiri atas 2 titik koleksi di daerah intertidal dan 2 titik di daerah subtidal. Penelitian di laboratorium dilakukan untuk karakterisasi morfologi, morfometri, dan identifikasi. Karakterisasi morfologi meliputi morfometri cangkang, pengamatan karakter eksterior cangkang, karakter interior cangkang, serta karakter anatomi. Data karakter morfologi dan karakter habitat dianalisis secara deskriptif, sedangkan data morfometri diolah secara kuantitatif dan dianalisis dengan regresi linier untuk mengetahui pola hubungan morfometri cangkang. Hasil penelitian menunjukkan bahwa di perairan Pantai Sidoarjo terdapat 13 spesies bivalvia, yaitu Anadara (Scapharca) gubernaculum (Reeve, 1844); A. (Scapharca) rufescens (Revee, 1844);, A. (Tegillarca) granosa (Linnaeus, 1758); A. (Tegillarca) nodifera (Martens, 1860); Potamocorbula faba (Hinds, 1843); Mactra (Mactra) queenslandica E.A. Smith, 1914; Heterocardia gibbosula Stoliczka, 1871; Siliqua sp.; Theora lata (Hinds, 1843); Tellina (Moerella) philippinarum Hanley, 1844; Paphia (Paphia) undulata (Born, 1780); Timoclea (Chioneryx) scabra (Hanley, 1844); dan Clamentia vatneleti Mabille 1910. Karakter morfologi pembeda setiap spesies antara lain berupa ukuran cangkang, tipe pahatan cangkang, tipe gigi engsel, tipe ligamen, lekuk palial, hubungan morfometri cangkang, ukuran dan tipe sifon, tipe dan bentuk insang (ctenidium), serta bentuk dan ukuran palpus labialis. Karakter habitat yang dapat digunakan sebagai pembeda adalah tipe substrat, salinitas air, dan kedalaman meliang. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa ketiga belas spesies yang terdapat di perairan Pantai Sidoarjo tersebut memiliki karakter morfologi yang khas, sesuai dengan habitatnya.

The purposes of this research were to know the diversity of bivalves at Sidoarjo coastal water and to study their morphological characters and habitat. The research was conducted in two steps. First step was done at Sidoarjo coastal water for specimen collection and habitat characterization. It was done at 5 research stations. Each station consisted of 3 line transects and each line transect consisted of 2 intertidal collection sites and 2 subtidal collection sites. Habitat characterization consisted of measurement of temperature, water salinity, and water and substrate acidity (pH) as well. Samples of substrate were also taken for further analysis. Second step was done in laboratory for morphological characterization and identification. Morphological characterization consisted of morphometric measurement and characters observation of shell exterior, shell interior, and internal anatomy. Data of morphological character and habitat were analyzed descriptively, while morphometric data was analyzed quantitatively and the morphometric relationship of the shell was analyzed by linear regression. The results showed that there were 13 species of bivalves, belong to 5 family and 5 genera. They were Anadara (Scapharca) gubernaculum (Reeve, 1844); A. (Scapharca) rufescens (Revee, 1844); A. (Tegillarca) granosa (Linnaeus, 1758); A. (Tegillarca) nodifera (Martens, 1860); Potamocorbula faba (Hinds, 1843); Mactra (Mactra) queenslandica E.A. Smith, 1914; Heterocardia gibbosula Stoliczka, 1871; Siliqua sp.; Theora lata (Hinds, 1843); Tellina (Moerella) philippinarum Hanley, 1844; Paphia (Paphia) undulata (Born, 1780); Timoclea (Chioneryx) scabra (Hanley, 1844); dan Clamentia vatneleti Mabille 1910. Diagnostic characters of each species were shell size, type of sculpture of the shell, type of ligamen, pallial sinus, morphometric relationship of the shell, size and type of sifon, type and form of ctenidium, and type and form of labial palp. Habitat characters could be used as diagnostic characters for species. They were type of substrate, water salinity, and the deep of burrowing. Based on the results, it could be concluded that all of those bivalve species have specific morphological characters that suitable for their habitat.

Kata Kunci : Bivalvia,Karakter morfologi,Habitat,Perairan pantai Sidoarjo, Bivalvia, bivalves, morphological character, habitat, Sidoarjo coastal water