First observation of the mating, egg-laying and hatching behaviour of a captive female Kong skate, Okamejei kenojei (Müller & Henle, 1841)

J Fish Biol. 2022 Oct;101(4):1084-1091. doi: 10.1111/jfb.15165. Epub 2022 Sep 1.

Abstract

This study provides a novel record of the reproductive behaviour of the Kong skate (Okamejei kenojei) in captivity. These skates were found to mate and deposit eggs at a temperature of 16.5 ± 0.5°C. The results showed that 76.13% of the eggs possessed one yolk, 0.77% of the eggs possessed two yolks and 23.11% of the eggs had no yolk (N = 1043). The deposition of non-yolk and double-yolk eggs was random. A total of 100 eggs were collected. After nearly 92 ± 5 days of incubation, 28 eggs failed to hatch, and 72 skates were successfully hatched with a female-to-male ratio of 1:1 (P > 0.05). The results enrich our knowledge of the reproduction in cartilaginous fishes and can inform management and conservation strategies for this species.

Keywords: Okamejei kenojei; egg capsule; reproductive behaviour; sex ratio.

MeSH terms

  • Animals
  • Egg Yolk
  • Female
  • Male
  • Oviposition
  • Parturition
  • Pregnancy
  • Reproduction*
  • Skates, Fish*
  • Temperature