Length-weight relationship, body condition, and fishing gear selectivity of shortfin scad (Decapterus macrosoma) landed in Banjarmasin fishing port, Indonesia

Abstract

The present study provides scientific information on the growth pattern and relative condition of shortfin scad, Decapterus macrosoma Bleeker landed in Banjarmasin fishing port, Indonesia. A total of 313 individual scad comprising 178 males and 135 females ranging from 152 to 225 mm total length and from 37 to 110 g weight were investigated. The body shape of both males and females showed isometric growth patterns indicating that all body dimensions grew at the same rate. The regression coefficient was significantly different between the sexes. The total length (TL), body weight (W), body depth (BD), W/TL, and BD/TL ratios and condition factors of the females were comparatively higher than those of males. The highest percentage of the catch was between 180 and 189 mm TL (32.59–40.45%) and 50 and 59 g W (20.65-21.79%). The relative condition factor values ranged from 0.799 to 1.433, which reflected the good condition of the fish samples. The estimated length at first capture (Lc50) and selection factor values were 180 mm and 3.54 for males and 185 mm and 3.64 for females. In the present work, the purse seine was considered to be a male-biased gear, with a sex ratio of 1.3 : 1. The outcomes of this research could be useful for sustainable pelagic fisheries management and for developing precautionary measures to prevent the overexploitation of this species.

Length-based population parameters of shortfin scad (Decapterus macrosoma) in Bali Strait waters, Indonesia

“…By the length at first captured of D. macrosoma in this study (184 mmFL), we know that most of the caught fish were large fish. A similar condition was also reported in which most of the captured D. macrosoma were large [40]. The Lc50 in this study is bigger than reported from the purse seine catch in the Java Sea (153 mmFL) [54] and Sibolga waters (131 mmFL) [13].…”

“…The hyperallometric growth pattern was also reported for D. macrosoma in Matang mangrove estuaries, Malaysia [37]. [40] reported that D. macrosoma from the Masalima Sea was isometric. Some factors that can affect this relationship are season [41][42][43], habitat and water quality [44,45], and availability of food [20,46].…”

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

“…Other reports showed that D. macrosoma found in the eastern water off Ambon Island, Maluku, Indonesia has positive allometric growth (Pattikawa et al 2017); however, negative allometric growth was recorded off Aceh waters (Afdhila et al 2019), and both negative and positive allometric growth in Banda waters, Maluku Province (Senen et al 2011). Isometric growth of D. macrosoma was also reported in the Java Sea (Prihatini et al 2017) and the Masalima Sea around Makassar Strait, Indonesia (Ahmadi 2020). A relative condition factor (Kn) value greater than 1 indicates the generally good condition of the fish (Le Cren 1951).…”

Biological aspects of roundscads (Decapterus spp.) inhabiting the waters of Southeast Maluku, Eastern Indonesia

“…Meanwhile, some researchers reported that spawning season of roundscads varies among species and locations. For example, D. macrosoma spawn in April-May in Makassar Strait (Ahmadi, 2020) while in Ambon Bay in July-August (Syahailatua & Sumadhiharga, 1991) and between July and November in Java Sea (Atmaja & Sadhotomo, 2005). Spawning season for D. macarellus in Tomini Bay in August (Widiyastuti & Zamroni, 2017) while in Celebes Sea occurs in March (Zamroni et al, 2019).…”