120 likes | 226 Views
Morphological and identification of fish larvae ( Acanthuridae, Gempylidae and Trichiuridae ) from Southeast Asia waters. by Kosum polrong. Review to morphological features. Acanthuridae Body shape :
E N D
Morphological and identification of fish larvae (Acanthuridae, Gempylidae and Trichiuridae )from Southeast Asia waters by Kosum polrong
Review to morphological features Acanthuridae Body shape : Pre flexion-body is moderate deep, strongly compressed laterally, they have 21-23 myomeres and the gut coiled. Flexion-deeper more than of body, snout have a triangular head and the mouth is small. The eyes a round and moderate to large size.
Spination : Pre flexion-the smaller spines is early appearance in larvae 1.8 mm have a bones such as supraoccipital crest serrate, preopercle, lower jaw, mid-ventral keel and pelvic girdle. Flexion-following presented of spines at the supracleithral, posttemporal, opercular serrate
Pigmentation Preflexion-The larvae pigment present on brain, gut, along throat, lower jaw, and dorsal surface of gas bladder. Flexion-In some species. The pigment occurrence on caudal peduncle and increase to heavy and density in late stage.
Similar families and genus Difference of characters - Zanclids not have large anal fin spine, the elongate of third dorsal fin spine and in preflxion stage have a longer than of preanal length. - Menids lack elongate fin spine and serrate crests or ridges of head. - siganids and leiogngsthids have larger than preopercular spines and sometime of myomeres number more than to 24
Table 1 Meristic characters larval of Acanthuridae(Ahlstrom, 1948; Leis and carson,2000;Richards, 2006; Chayakul, 2007) a = present study B = from review
Specimens data Participant : Mr. Pitoon puewkhao Family : Acanthuridae Generic name : Naso sp. Sampling locality : Andaman sea Sampling gear : Bongo net Stage: Flexion
Measurements of data - Body length(BL) = 5.30 mm. - Head length(HL) = 2.20 mm. - Eye diameter(ED) = 0.50 mm. - Snout length(SnL) = 1.20 mm. - Preanal length(PAL) = 1.93 mm. - Body depth(BD) = 4.20 mm.
Figure A. Naso sp.2.20 mm.(Leis and carson, 2000)Figure B. Naso sp.3.80 mm.(Leis and carson, 2000)
Morphological features Body shape : - Very deep(79.26%) - Large head(41.51%) - Small eye(22.73%) Gut : - Coiled Head spination - Supraocipital crests and spraocular
Pigmentation The pigment present on brain, around of abdominal cavity, pectoral fin base and caudal peduncle. All pigment increase to heavy and density in late stage.