Embryonic development in giant cuttlefish Sepia latimanus
Journal of National Fisheries University Volume 71 Issue 3
Page 81-87
published_at 2023-03
Title
コブシメの胚発生
Embryonic development in giant cuttlefish Sepia latimanus
Abstract
Embryonic development in giant cuttlefish Sepia latimanus was studied using eggs laid from broodstocks reared in captive condition. 26 embryonic stages were examined in this study and the detail process of organ development was clarified under microscope observation. Blastdisc was visible at the animal pole on the yolk at 2.5 hours after fertilizaton (HAF). The first cleavage occurred at 8.6 HAF. Then embryo developed to the morula stage at 22 HAF. Almost surface of the egg was covered with blastoderm at 10 days after fertilization (DAF). Primordia of main organs such as arms, mouth, mantle, funnel, optic vesicle, gills, statocyst, lens and optic ganglion were formed till 14 DAF. At 15 DAF calcification began in the first striation on the shell. Primordium of the shell became visible at 18 DAF. The number of striations on the shell reached to 5, 9 and 14 at 26, 32 and 40 DAF, respectively. Embryo needed 45 days for hatching. Newly hatched larva was 14 mm in mantle length and had 18 striations on the shell. The process of embryonic development in S. latimanus was very similar as S. lycidas, S. esucurenta and Sepiella japonia. S. latimanus is characterized with large newly hatched larva in Japanese sepiids. It was revealed that the large yolk of S. latimanus induces the growth of the body over a long period in the embryonic stage.
Creators
Oka Masakazu
Creators
Tezuka Nobuhiro
Source Identifiers
[PISSN] 0370-9361
Creator Keywords
embryonic development
Sepia latimanus
giant cuttlefish
large yolk
Languages
jpn
Resource Type
departmental bulletin paper
Publishers
National Fisheries University
Date Issued
2023-03
File Version
Version of Record
Access Rights
open access
Relations
[ISSN]0370-9361