POPULATION DYNAMICS AND AQUACULTURE POTENTIAL OF THE MUD CLAM, Geloina expansa (MOUSSON, 1849) (BIVALVIA: CYRENIDAE) IN LOAY-LOBOC RIVER, BOHOL, CENTRAL PHILIPPINES

Abstract

The status of the mud clam, Geloina expansa, an important bivalve in the artisanal fisheries of the Loay-Loboc River, was assessed using monthly shell length frequency data (October, 2012 to January, 2015 to estimate population parameters. Growth parameters derived were L ∞ = 91.35 mm, K = 0.75 yr -1 and t 0 = -0.16. Predicted L max was 90.39 mm. Estimated growth rates showed fast growth for the first two years. Longevity is approximately 6.1 years. Length-weight relationship showed a positive allometric growth (r 2 = 0.94). The estimated total mortality (Z) was 2.89 yr -1 . Natural (M) and fishing (F) mortalities estimates were 0.90 yr -1 and 1.99 yr -1 , respectively. Estimated exploitation rate (E = 0.69) was higher than the maximum sustainable exploitation (E max = 0.41). Two annual recruitment peaks occurred during the months of December to February and July to August. Monthly condition index (CI) suggested that spawning is year-round. It appeared that the variations in CI of G. expansa in the river was influenced by the water temperature and salinity (r² = 0.54; P < 0.0001). These biological information may be used for aquaculture technique development for G. expansa in central Philippines which will aid in the conservation and management of natural stocks.

Population dynamics of blood clams Tegillarca granosa in Kendari Bay, Southeast Sulawesi, Indonesia

“…celebensis (Bahtiar 2012;Bahtiar et al 2016) and Polymesoda erosa (Dolorosa and Dangan-Galon 2014) (Table 2). The natural mortality of the blood clams was 2.18 yr -1 , and it was similar to that of others in the same genus, including A. granosa (Mirzaei et al 2014) and A. gubernaculum (Fauzan et al 2018), but higher than Polymesoda expansa (Argente and Ilano 2013), Potamocorbula faba (Hariyadi et al 2017), Donax trunculus (Çolakoğlu 2014), Geloina expansa (Yahya 2017), P. erosa (Dolorosa and Dangan-Galon 2014), P. acutidens (Efriyeldi et al 2012), andB. violacea var.…”

“…celebensis along 2 km, especially in smaller species (Bahtiar 2012;Bahtiar et al 2016). 2016) Descriptions: Z: mortality coeffiecient (yr -1 ); M: natural mortality coefficient (yr -1 ); F: fishing mortality coefficient (yr -1 ); E: exploitation rate The fishing mortality of the blood clams in Kendari Bay was 0.29yr -1 , and this was higher than that of other species, namely P. expansa (Argente and Ilano 2013), and Potamocorbula faba (Hariyadi et al 2017). Meanwhile, the value obtained was similar to that of some clams, as shown in Table 3.…”

MORPHOLOGICAL MEASUREMENT AND ABUNDANCE OF MANGROVE CLAM (Geloina expansa) AND ITS SEDIMENT GRAIN SIZE PREFERENCES AT PULAU SUTUNG AND PULAU BUSUNG, SETIU WETLANDS, TERENGGANU

“…These measurements are lower than this present study (Table 1). According to Argente and Ilano (2021)…”

Population dynamics of mud clam Geloina expansa (Mousson, 1849) in degraded mangrove area at Kendari Bay, Indonesia

“…On the other hand, the high activity in the upland section of Kendari Bay, as the center of all community activities around Kendari City and South Konawe areas, exacerbates the decline of G. expansa, whose life depends on the quality of the environment and the substrate in the mangrove ecosystem (Idris et al 2017;Bahtiar et al 2023), marked by the high natural mortality of G. expansa populations in mangrove waters. Several species of Polymesoda or Geloina clams, such as: Polymesoda solida R.A.Philippi, 1846, Polymesoda arctata Deshayes, 1855 (Argente and Ilano 2013;Dolorosa and Dangan-Galon 2014), have been exploited on large scales because of their high economic values (Yahya et al 2018;Ransangan et al 2019). These clams have been served as grilled/satay dishes at roadside and restaurants in Marudu Bay (Duisan et al 2021) or as additional feed to induce gonad maturation of raw crabs in hatcheries (Thien and Yong 2017).…”

“…Research on population dynamics of G. expansa has been carried out in several places (Argente and Ilano 2013;Dolorosa and Dangan-Galon 2014;Yahya et al 2018;Ransangan et al 2019), while in the same area, it has been carried out for a limited time (3 months) (Tamsar et al 2013). Therefore, it is important to conduct research on population structure, growth, mortality and exploitation rates of G. expansa in the mangrove forests of Kendari Bay, Southeast Sulawesi, Indonesia so that the appropriate actions can be undertaken to maintain the continuity of life of G. expansa (Akbar and Ishak 2014).…”