Effects of light on reproduction of the Mediterranean medicinal leech, Hirudo verbana Carena, 1820: do circadian rhythm disruptions positively affect reproductive performance of leeches?


CEYLAN M., ÖZDOĞAN H. B. E., Tunay M.

Invertebrate Reproduction and Development, vol.68, no.3, pp.135-140, 2024 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 68 Issue: 3
  • Publication Date: 2024
  • Doi Number: 10.1080/07924259.2024.2375069
  • Journal Name: Invertebrate Reproduction and Development
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.135-140
  • Keywords: cocoon, gravidity, Light regulation, offspring
  • Isparta University of Applied Sciences Affiliated: Yes

Abstract

This study aimed to assess the impact of light on the reproductive performance of leeches for the first time using the Mediterranean medicinal leech Hirudo verbana Carena, 1820, which is important in medicinal leech aquaculture. Gravid leeches were subjected to three different light conditions: 24-h Light, 24-h Dark, and Daylight (14-h light and 10-h dark) for 11 weeks. Gravidity ended at the 8th week for the Dark (5.33 ± 0.38 weeks) and Daylight (5.41 ± 0.29 weeks) groups, whereas it persisted for 11 weeks in the Light group (6.75 ± 0.51 weeks) (p = 0.031). In comparison to the Daylight group (cocoons: 40, offspring: 538), the Light (cocoons: 50, offspring: 723) and Dark (cocoons: 45, offspring: 576) groups achieved a greater yield of cocoons (p = 0.312) and offspring (p = 0.323). We invite discussion on the notion that the enhanced reproductive capacity of leeches in full light and full dark conditions, as opposed to daylight, may be attributed to the disturbance of their circadian rhythms.