Induced breeding and embryogenesis of vermiculated spine foot, Siganus vermiculatus, in captivity
Volume 67 Issue 1
A. Anuraj, P. P. Suresh Babu, Tanveer Hussain, R. Siju, Jayasree Loka, Mahendra Pal,
N. Anjulekshmi, K. S. Aneesh and Boby Ignatius
doi:10.6024/jmbai.2025.67.1.2576-08
Abstract
Siganus vermiculatus, commonly known as the vermiculated spinefoot, is one of the most promising mariculture species within the Siganidae family due to several advantageous characteristics.The present study investigated the broodstock development, induced breeding, and embryonic development of the S. vermiculatus. Wild-caught specimens (211-325 g) were collected from Kali estuary (14 °51’0’’ N and 74 °8’ 0’’ E), Karwar, Uttara Kannada and reared in marine cage farm conditions for six months (April to September 2021). Mature brooders were selected through cannulation, with breeding induced using LHRH-a (20 μg/kg) administered intramuscularly. Spawning occurred during the third quarter of the lunar cycle, approximately 20 h, 15 min. post-injection. Fertilized eggs were spherical, demersal, adhesive, and transparent, measuring 0.56 ± 0.03 mm. Embryonic development proceeded through characteristic teleost patterns, beginning with meroblastic discoidal cleavage resulting in a 2-cell stage at 18 min. post-fertilisation. Subsequent development included blastula formation, yolk syncytial layer, epiboly, embryonic shield, axis establishment, somite formation, optic bud and otic vesicle development, and cardiac function initiation. Embryonic movements began at 16 h 15 min., with hatching occurring between 22 h 39 min. and 23 h 55 min. at 32 ppt and 29.5± 0.4 °C. Newly hatched larvae measured 1.9 ± 0.11 mm in total length with an initial yolk volume of 0.015±0.003 mm 3 and oil globule volume of 0.004± 0.001 mm 3 . This detailed characterization of S. vermiculatus embryonic development
contributes valuable information to teleost developmental biology and provides essential knowledge for optimizing hatchery protocols, potentially enhancing aquaculture production of this commercially important species.
