Phenotype characterization of interspecific hybrid abalone Haliotis asinina and Haliotis squamata seed

<p class="NoParagraphStyle" align="center"><strong>ABSTRACT</strong></p><p class="NoParagraphStyle" align="center"><strong> </strong></p><p class="NoParagraphStyle">Abalone is one of sea-water aquaculture commodity that having relatively low in growth and survival. Interspesific hybridization between abalone <em>Haliotis asinina</em> and <em>Haliotis squamata</em> is required to produce hybrid seeds having a better phenotype inherited from their parents. Crossbreeding of abalone was done in the reciprocal procedure with a natural spawning technique on mass scale. The hybrid seeds showed higher similarity with female brood (98,69%), while the larvae from <em>H. squamata </em>× <em>H. asinina</em> were abnormal on trocophore until early veliger phase then dead occurred the next phase. The results showed that hybridization between male <em>H. asinina</em> and female <em>H. squamata</em> had higher fertilization and hatching rate than its reciprocal i.e. 76.01±6.15% and 60.14±4.80%.</p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle">Keywords: interspesific hybridization, phenotype, <em>Haliotis asinina</em>, <em>Haliotis squamata</em>, abalone</p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle" align="center"><strong>ABSTRAK</strong></p><p class="NoParagraphStyle" align="center"><strong> </strong></p><p class="NoParagraphStyle">Abalon merupakan komoditas budidaya laut dengan pertumbuhan yang relatif lambat dan kelangsungan hidupnya rendah. Rekayasa persilangan interspesifik antara abalon <em>Haliotis asinina</em> dan <em>Haliotis squamata</em> diharapkan mampu mengatasi permasalahan benih dan memiliki fenotipe unggul yang diwariskan dari tetuanya. Persilangan abalon dilakukan secara resiprok dengan teknik pemijahan alami skala massal. Hasil penelitian menunjukkan bahwa benih hibrida menunjukkan kemiripan dengan induknya sebesar 98,69%, sedangkan larva hibrida antara jantan <em>H. squamata </em>× <em>H. asinina</em> menunjukkan bentuk abnormal pada fase trokofor hingga veliger awal dan kematian pada fase lanjut. Hibridisasi antara jantan <em>H. asinina</em> dan betina <em>H. squamata</em> memiliki derajat pembuahan dan derajat penetasan yang lebih tinggi dibandingkan resiprokalnya, yaitu berturut-turut 76,01±6,15% dan 60,14±4,80%.</p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle">Kata kunci: hibridisasi interspesifik, fenotipe, <em>Haliotis asinina</em>, <em>Haliotis squamata</em>, abalon</p><p> </p><p class="NoParagraphStyle" align="center"> </p>

Eggs, larvae, and spawning in Melarapha cincta (Quoy & Gaimard) and M. oliveri Finlay (Littorinidae, Gastropoda)

Both the New Zealand species of Melarapha, M. cincta and M. oliveri, laid minute planktonic egg capsules, of the "Drum" type, in the laboratory. Capsules were similar in the two species, but could be distinguished in side view by shape. Eggs developed rapidly, hatching at an early veliger stage in 3-4 days at room temperature. Attempts to rear these very small larvae were not successful, but later veligers, taken from plankton hauls, were reared through metamorphosis and identified as Melarapha. Veliger stages are drawn and described and the length of planktonic life assessed as 1-2 months. The two species are indistinguishable after hatching until many months after metamorphosis when the adult coloration of the shell is developed. Spawning was studied at Portobello in a mixed population of M. cincta and M. Oliveri extending from high HWS to low HWS. The breeding season was from November to March. Spawning, in animals associated with rock pools, occurred intermittently and not particularly during spring tides. The presence of egg capsules of both species in rock pool samples was associated ( χ² tests) with a rock pool salinity of 33-36‰ and with the occurrence of rough weather.