Indian Journal of Animal Research
SCOPUSWeb of Science
  • Year: 2026
  • Volume: 60
  • Issue: 9

Histological Observations on Oocyte Development in the Fourfinger Threadfin (Eleutheronema tetradactylum)

  • Author:
  • Tanveer Hussain1,2,4*, M. Kailasam3, Prem Kumar2, A.K. Verma2, V. Mahesh4, Kurva Raghu Ramudu4, Tarunkumar V. Harijan4, Debajit Sarma2
  • Total Page Count: 7
  • Page Number: 1624 to 1630

1Navsari-Gujarat Research Center, ICAR-Central Institute of Brackishwater Aquaculture, Navsari Agricultural University Campus, Navsari-396 450, Gujarat, India

2Division of Aquaculture, ICAR-Central Institute of Fisheries Education, Mumbai-400 061, Maharashtra, India

3ICAR-Central Institute of Brackishwater Aquaculture, R.A. Puram, Chennai-600 028, Tamil Nadu, India

4Karwar Regional Station of ICAR-Central Marine Fisheries Research Institute, Karwar-581 301, Karnataka, India

*Corresponding Author: Tanveer Hussain, Karwar Regional Station of ICAR-Central Marine Fisheries Research Institute, Karwar-581 301, Karnataka, India, Email: tanveer716@gmail.com

Abstract

Comprehensive information on oocyte growth and ovarian development patterns (synchronous or asynchronous) is lacking. Therefore, the present study aimed to study oocyte growth and ovarian development patterns in Eleutheronema tetradactylum collected from the Gujarat coast of India from September 2021 to August 2022.

333 female E. tetradactylum were collected from the Navsari coast, Gujarat, India. Macroscopically, determined gonads were preserved in 10% neutral buffered formalin and processed for histology. Ovaries preserved in Gilson’s fluid were examined for oocyte size and development pattern, with 150-400 oocytes per fish measured in a microscope.

The results revealed that E. tetradactylum oocytes development stages were classified into five developmental stages. (i) pre-vitellogenic (ii) vitellogenic (iii) late-vitellogenic (iv) postvitellogenic and (v) follicular atresia. The oocyte attained the maturation stage at 550-650 µm. Histological observation and percentage distribution of oocyte types revealed that the E. tetradactylum is an asynchronous and multiple spawner fish species. In the various ovarian maturity stages, the presence of different stages of oocytes confirms asynchronous oocyte growth. Furthermore, the pattern of continuous oocyte size frequency in maturing to the ripe stage indicates a batch spawning strategy. The findings provide essential baseline data for assessing oocyte maturity and optimizing hormonal induction protocols in artificial breeding programs.

Keywords

Asynchronous, Batch spawner, Eleutheronema tetradactylum, Oocyte development, Oocyte size