Population Parameters of Shortfin scad Decapterus macrosoma (Bleeker, 1851) in Antique, Philippines

Abstract

Growth, mortality, exploitation rate, and recruitment of Decapterus macrosoma in the waters off Antique province, Philippines, were investigated based on the length-frequency data collected from April 2019 until March 2020. Using the FISAT-II software, D. macrosoma growth parameters were computed as follows: L∞ = 26.18 cm TL, K = 1.00 yr-1, ø' = 2.836 yr-1, and an estimated life span of 3 years. Mortality values were estimated as: total mortality (Z) = 4.66 yr-1; natural mortality (M) = 1.88 yr-1; and fishing mortality (F) = 2.78 yr-1. The exploitation rate (E) was computed as 0.60 while Emax was 0.42 yr-1. The length at first capture Lc/L50 was estimated at 11.96 cm TL. There were two recruitment events in one year: July and December. D. macrosoma in Antique was growing isometrically and in good condition with the relative condition factor (Kn) values ranging from 0.99 to 3.39. The computed exploitation rate suggested that D. macrosoma faces a high level of exploitation in Antique waters. These results offer valuable information on the utilization, conservation, and management of D. macrosoma in the East Sulu Sea area.

First Report on the Reproductive Biology of the Redtail Scad Decapterus kurroides Bleeker, 1855 in Iligan Bay, Southern Philippines

“…Fecundity estimates for D. kurroides in this study are the first record for the species. Its maximum fecundity of 197, 672 eggs per female is relatively higher than D. russelli, which recorded a maximum absolute fecundity of 152,123 eggs per female (Poojary et al 2015), and D. macrosoma with 106,000 eggs per female (Tiews et al 1971). With this, D. kurroides in Iligan Bay has a higher potential number of offspring and higher reproductive capacity than other round scad species.…”

“…In Mangaluru Coast, India, round scads, especially D. russelli, mature at a length of 16.0-18.0 cm TL (Ashwini et al 2016), similar to D. kurroides in Iligan Bay. In contrast, D. macrosoma, which has a maximum length of 35.0 cm (Smith-Vaniz 1986), would achieve maturity between 18.0 cm and 20.0 cm in the waters of Palawan and Manila Bay (Tiews et al 1971). The exceptionally low length at maturity of D. kurroides may represent a compensatory reaction of the resource to elevated mortality caused by fishing (Rochet and Marty 2009).…”

“…This study was the first attempt to describe the reproductive characteristics of the commercially important D. kurroides. Existing literature concerning D. kurroides mainly dealt with stock assessments and growth studies (Lavapie-Gonzales 1991; Lavapie- Gonzales et al 1997;Pastoral et al 2000;Wang et al 2011;Palla et al 2018;De Guzman and Rosario 2020), the concentration of trace elements in the tissues (Agusa et al 2005), morphology (Chang et al 1976;Tzeng et al 2003), and parasitic infestation (Ho et al 2000;Amin et al 2011; Cruz-Lacierda and Nagawasa 2017) while reproductive biology studies were limited only to other Decapterus species (i.e., Tiews et al 1971;McBride et al 2002;Ohshimo et al 2006;Shiraishi et al 2010;Rada et al 2019).…”

Population Dynamics of Shortfin Scad (Decapterus macrosoma) Bleeker 1851 in Babuyan Channel, Philippines

“…Length frequency data for all gears were validated and L max was established following the Binohlan and Froese (2009) model. The largest L max observed in the study was 32.8 cm, however, this measurement seems too big for the species and questionable since most of the recorded and published length for this species was only up to 29.5 cm (Lavapie-Gonzales et al 1997;Belga et al 2018;Magallanes et al 2022;. Applying the equation of Binohlan and Froese (2009), the species of D. macrosoma in the Babuyan Channel that matures at 17.64 cm would predict an L max of 31.46 cm.…”

Hubungan Panjang-Bobot, Pola Pertumbuhan Dan Faktor Kondisi Ikan Pelagis Kecil Di Perairan Sukabumi Dan Lebak

“…Diduga ketersediaan makanan di perairan Sukabumi dan Lebak cukup untuk mendukung pertumbuhan ikan kembung lelaki dan ikan layang. Magallanes et al (2022) menyatakan bahwa cukupnya ketersediaan makanan memengaruhi nilai faktor kondisi yang baik untuk pertumbuhan ikan. sebagaimana dinyatakan oleh Pouladi et al (2020), kesesuaian perairan bagi pertumbuhan ikan dapat dilihat dari nilai faktor kondisi karena dapat mengindikasikan tersedianya makanan dan kondisi habitat yang baik.…”