Embryology and early ontogeny of an anemonefish Amphiprion ocellaris

Abstract

The present study describes the embryonic development and early ontogeny of Amphiprion ocellaris from fertilization to post hatching. Anemonefish spontaneously spawned at 27-28°C. The newly laid eggs were orange in colour and elliptical in shape (1.8×0.8 mm). Melanin appeared as a black mass situated at the vegetal pole in mature eggs. This is rarely seen in eggs of other fish species. We documented developmental times at 27-28°C to egg activation (0.5 h), cleavage (4 h), blastula (11.5 h), gastrula (20 h), neurula (24.5 h), somite (28.5 h), turnover (72 h), blood formation (113 h) and internal ear and jaw formation (144 h). Hatching occurred 152 h after fertilization. On day 4, the eye buds were pigmented and melanophores formed on the ventral surface of the embryo. Internal ear and gill formation were completed on day 5 and coincided with movement of the opercula and pectoral fins. The mouth formed on day 6 and the digestive tract appeared on day 7. By day 10, the yolk was fully absorbed and a substantial amount of food was observed in the gut. Dark and orange pigments were dispersed and aggregated through muscle contractions by day 14, but red pigments did not appear until the fish were three months old. This study contributes to a further understanding of the embryology and the early ontogeny of damselfish and may help improve the culture of coral reef fish.

Clownfish

“…The characteristic ontogenesis of the eye, that develops a strong metallic silver color throughout time, is useful for following embryo development and predicting hatching. Liew et al (2006) and Yasir & Qin (2007) investigated the embryo development process in A. ocellaris at 27-28 °C and found consistent differences in the development rate. Generally, incubation lasts for 6 to 8 days at water temperature of 28 °C for most clownfish species (Olivotto et al, 2008a,b;Dhaneesh et al, 2009.…”

“…Liew et al (2006) and Yasir & Qin (2007) investigated the embryo development process in A. ocellaris at 27-28 °C and found consistent differences in the development rate. Yasir and Qin (2007) found that the development rate is first slower than in Liew et al (2006) but then drastically increased. In Yasir and Qin (2007) the first cleavage appeared at 4 hpf, blastula at 11.5 hpf, gastrula at 20 hpf, neurula at 24.5 hpf, first somites at 28.5 hpf and hatching occurred 152 hpf.…”

“…Generally, incubation lasts for 6 to 8 days at water temperature of 28 °C for most clownfish species (Olivotto et al, 2008a,b;Dhaneesh et al, 2009. In Yasir and Qin (2007) the first cleavage appeared at 4 hpf, blastula at 11.5 hpf, gastrula at 20 hpf, neurula at 24.5 hpf, first somites at 28.5 hpf and hatching occurred 152 hpf. In Liew et al (2006), the first cleavage appeared at 1.2 hours post-fertilization (hpf ), blastula at 4 hpf, gastrula at 12 hpf, neurula at 20.5 hpf, first somites at 24 hpf and hatching at 180.5 hpf.…”

PERKEMBANGAN EMBRIO DAN LARVA IKAN LETTER SIX, Paracanthurus hepatus

“…Berbeda dengan ikan hias clown hitam (Amphiprion percula) yang memiliki bentuk lonjong dengan kisaran ukuran yang relatif lebih besar dari telur ikan letter six dengan ukuran 2,21 x 0,89 mm (Kusumawati & Setiawati, 2010). Sedangkan pada ikan clown biasa (Amphiprion ocellaris) memiliki bentuk lonjong dengan ukuran 1,8 x 0,8 mm (Yasir & Qin, 2007), sementara itu, pada jenis ikan clown lainnya yaitu Amphiprion akallopisos memiliki kisaran ukuran 2,21 x 1 mm (Dhaneesh et al, 2011). Pada ikan hias lainnya yaitu dari jenis ikan goby (Priolepis nocturna) memiliki bentuk oval dengan ukuran lebih besar dari ukuran telur ikan letter six yaitu 0,82 x 0,51 mm (Wittenrich et al, 2007).…”

“…Durasi perkembangan embrio ikan letter six terjadi dalam waktu 22 jam 24 menit (Tabel 1). Dalam kondisi suhu air yang sama yaitu berkisar 27°C-28°C, perkembangan embrio ikan letter six relatif lebih cepat jika dibandingkan dengan ikan hias laut dari jenis Amphiprion di mana pada ikan A. ocellaris dan A. kallopisos memerlukan waktu yang sangat lama yaitu 152 jam (Yasir & Qin, 2007;Dhaneesh et al, 2011). Sedangkan pada ikan jenis goby (Priolepis nocturna) memerlukan waktu 96 jam untuk larva bisa menetas (Wittenrich et al, 2007).…”