DOI: 10.14466/CefasDataHub.163

Description

Gonadosomatic Index (GSI) data was gathered as part of work looking into breeding season of Ballan wrasse. Fish samples were obtained from March 2018 to May 2019. Samples were obtained via local fishers using pots, traps and rod and line and subsequently processed back at the lab. Both fish weight (WT to nearest g) and gonad weight (WG, to 0.1g) were obtained in order to ascertain the GSI. The data set comprises of female fish from the Weymouth bay area from March 2018 to May 2019. The minimum GSI observed was 0.039GSI and Maximum observed 8.904GSI. The data shows the GSI in relation to the time of year the fish were captured.

175 Ballan wrasse were provided in 20 batches between March 2018 and May 2019 by inshore fishers. The fish were captured from Weymouth Bay on the south coast of the UK (ICES area VIIE 30E7). During the month of November through to July the wrasse were by-catch from lobster/crab pots and static nets. For the rest of the year (July to October), the fish were caught as a targeted species using fish traps and rod-and-line. This is in keeping with the seasonal fishing methods and reflects the only opportunity to obtain fish.

The fish were measured for total length (LT to nearest 0.5 cm) and total body weight (WT to nearest g). The body cavity was opened for sex determination. The ovaries of ballan wrasse are above the gut and arranged as a paired elongated lobular structure. Testes are often firmer, milky white or pink in colour. The gonads were removed and weighed (WG, to 0.1 g) for calculation of the gonadosomatic index (GSI).

GSI= (WG / WT) *100

Contributors

White, Peter / Ellis, Tim

Subject

Fish reproduction / Age / Aquaculture / Conservation / Fish / Fisheries

Start Date

01/01/2018

End Date

30/12/2019

Year Published

2025

Version

1

Citation

White and Ellis. (2025). Gonadosomatic Index of individual Ballan Wrasse caught from Weymouth Bay 2018 to 2019. Cefas, UK. V1. doi: https://doi.org/10.14466/CefasDataHub.163

Rights List

Open Government Licence

DOI

10.14466/CefasDataHub.163