Biometric indices and population parameters of three polynemid fishes from Batang Lassa Estuary of East Malaysia

M Golam Mustafa; Amy Halimah Rajaee; Hadi Hamli; Khairul Adha A Rahim

doi:10.7717/peerj.12183

Biometric indices and population parameters of three polynemid fishes from Batang Lassa Estuary of East Malaysia

PeerJ. 2021 Oct 15:9:e12183. doi: 10.7717/peerj.12183. eCollection 2021.

Authors

M Golam Mustafa^{1

2}, Amy Halimah Rajaee^{1

3}, Hadi Hamli¹, Khairul Adha A Rahim⁴

Affiliations

¹ Department of Animal Science and Fishery, Faculty of Agricultural Science and Forestry, Universiti Putra Malaysia Bintulu Sarawak Campus, Bintulu, Sarawak, Malaysia.
² Department of Oceanography, Noakhali Science and Technology University, Noakhali, Bangladesh.
³ Institut Ekosains Borneo, Universiti Putra Malaysia Bintulu Sarawak Campus, Bintulu, Sarawak, Malaysia.
⁴ Department of Aquatic Science, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia.

Abstract

The length-weight relationships (LWRs), condition factor (Kn), growth, mortality and exploitation status of three polynemid fishes, i.e., Filimanus xanthonema (Valenciennes, 1831), Polynemus melanochir (Valenciennes, 1831) and Polynemus paradiseus (Linnaeus, 1758) from Batang Lassa River estuary were estimated. Fish samples were caught during April 2019 to September 2020 using the ESBN (locally called Gnian) having 1.25 to 4.00 cm mesh size. The total length (TL) and body weight of each individual fish was measured to the nearest 0.1 cm and 0.01 g respectively. The growth coefficients (b) for F. xanthonema, P. melanochir and P. paradiseus, were 2.880, 2.717 and 2.724 with the R ² values 0.956, 0.972 and 0.936 respectively. Estimated growth coefficients indicated a negative allometric growth pattern for all three threadfin fishes. To date, information regarding length-weight relationships for F. xanthonema and P. melanochir is insufficient whereas the information is available for P. paradiseus. About 40-48% of fishes exhibited flat or thin body shape (Kn < 1), 48-50% were rounded or fat (Kn > 1) and only 1-3% of fishes showed proportional body shape (Kn = 1). The growth parameters L_∞ , K and ϕ' were estimated at 15.75 cm, 0.95 yr^-1 and 2.37 for F. xanthonema; 27.61 cm 0.87 yr^-1 and 2.82 for P. melanochir; and 27.30 cm, 0.58 yr^-1 and 2.64 for P. paradiseus; respectively. The estimated natural mortality (M) included 2.10, 1.69 and 1.30 yr^-1; the fishing mortality (F) 0.57, 0.67 and 0.60 yr^-1; and exploitation ratio (E) 0.21, 0.28 and 0.31 for F. xanthonema, P. melanochir and P. paradiseus respectively. The study concluded that the stocks are still under exploitation (E < 0.5) condition. However, the studied Batang Lassa estuary could be a potential nursery ground considering the minimum lengths of 5.0, 3.8 and 4.0 cm for F. xanthonema, P. melanochir and P. paradiseus respectively. Therefore, management initiatives are needed to escape juvenile catches.

Keywords: Body shape; Growth and mortality; LWRs; North-West Borneo Island; Recruitment; Threadfin fishes; Tropical deltaic estuary.

Grants and funding

The research work was supported by the Ministry of Higher Education, Malaysia under the Fundamental Research Grant Scheme (FRGS/1/2019/WAB09/UPM/02/2; Project no. 07-01-19-2209FR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.