00000ctm a22000004a 4500 UP-8027390931313939379 Buklod 20150803154940.0 m |o d | ta 150803s2010 xx d r |||| u| (iLib)UPVIS-00038156222 Gift VML/nllb/09/19/2016 eng LG 995 2010 F5 A84 Ates, Maria Charmela D. Comparative study on the embryonic development of mud crabs scylla spp. by Maria Charmela D. Ates. Miagao, Iloilo University of the Philippines in the Visayas 2010 xi, 73 leaves. Thesis (M. S. Fisheries - Fisheries Biology) - Institute of Marine Fisheries and Oceanology, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, March 2010. Morphological changes in embryos, egg size, incubation period, duration of spawning from time of ablation, and morphological characters of newly hatched zoea of the three mud crabs species found in the Philippines under the genus Scylla were observed. The three species exhibited similar embryonic development with 10 embryonic stages : precleavage, cleavage, multicell, intermediate, multi-gastrula, naupliar, eye formation, thoracico-abdominal, heartbeat, and prehatch. S. serrate had the largest mean egg diameter, which was significantly larger (p<0.05) at the prehatch stage. Moreover, S. serrate had the largest mean egg volume, which was significantly larger (p<0.05) at the naupliar and prehatch stages. On the other hand, both the mean egg diameter and egg volume of S. tranquebarica and S. olivacea were similar (p>0.05). Mean egg volume increased almost twice the initial volume at the end of incubation. Incubation period was longest in S. serrate and shortest in S. olivacea. There was a positive relationship between egg size and larval size, as S. serrate exhibited the largest egg size and first zoea. However, no correlation was detected between egg size at prehatch stage and lengths of larval characters. The three species exhibited similar lengths of cephalic characters (p>0.05), but S. olivacea had significantly shorter (p<0.05) abdominal character lengths. Duration of spawning in captivity from the time of ablation was shortest in S. tranquebarica and longest in S. olivacea, with the latter species comparable to that in S. serrate. The study provides information on the biology of the three Scylla species that is relevant to hatchery production, aquaculture and fisheries management depending on the target species. Comparative study. Embryonic study. Mud crabs. Scylla spp. Quinitio, Gerald F., Ph.D. Chair (Thesis Committee). UPVIS UPV-CFOS LG 995 2010 F5 A84 UPVIS UPV-GL LG 995 2010 F5 A84 Thesis