Some population parameters of Ruditapes philippinarum (Bivalvia, Veneridae) on the southern coast of the Marmara Sea, Turkey

Abstract

Ruditapes philippinarum, a venerid clam, is a dominant species in the sandy and muddy areas in the coastal waters of the Marmara Sea. Intensive commercial harvesting of this species is conducted in these regions. We studied the population dynamics of R. philippinarum on the southern coast of the Marmara Sea (Bandırma). Samples were collected on a monthly basis between September 2012 and August 2013. Seasonal von Bertalanffy growth parameters using the length-frequency distribution of R. philippinarum were estimated at L ? = 67.50 mm and K = 0.33 year -1 , and the seasonal oscillation in growth rate was 0.53. The slowest growth period was in January. The growth performance index and potential lifespan were 3.182 and 8.06 years, respectively. The growth relationship was confirmed to have a positive allometric pattern. The average total mortality rate was estimated to be 0.777 year -1 , whereas the natural and fishing mortality rates were 0.539 and 0.238 year -1 , respectively. The current exploitation rate of R. philippinarum was 0.306. The recruitment pattern peaked during June-August, and spawning occurred between May and August. The results of this study provide valuable information on the status of R. philippinarum stocks.

Reproductive cycle of the Manila clam (Ruditapes philippinarum): an intensively harvested invasive species in the Tagus Estuary (Portugal)

“…Differences in water temperature during periods of gonad maturation and spawning might also be responsible for the highly variable spawning patterns exhibited by populations of R. philippinarum introduced in the Atlantic Ocean and Mediterranean Sea (Çolakoğlu & Palaz, 2014). In the present study, such variability was evidenced by monthly fluctuations in the GI clearly induced by the seasonal variation in water temperature in the Tagus Estuary.…”

Decline of the Manila clams stock in the northern Adriatic lagoons

“…The size class analysis showed a reduction of adult modal size class from July 2002 to April 2003, which could be due to the spring juvenile recruitment. The bimodal shape of the size class frequency distribution in October 2003 highlighted the presence of two cohorts (ÇOLAKOĞLU & PALAZ, 2014;MUNROE, 2016). The first one (modal class 3.7 cm) was the oldest generation which increased in size of about 0.5 cm compared to April 2003 (modal class 3.2 cm), the second one (modal class 2.7 cm) was the following generation, settled in the 2002, partially escaped to the harvesting and therefore available for the next year.…”

“…); c) individual mean harvested fresh mass in each month (+ s.e. )Japan(HASEGAWA & HIGANO, 2010), within species native area, allometric coefficients, as well as population parameters, may slightly change among locations and according to environmental and climatic conditions(ÇOLAKOĞLU & PALAZ, 2014).…”

Population structure and growth of the beaked clam Eumarcia paupercula (Bivalvia, Veneridae) in Maputo Bay, Mozambique

“…Figure 5 shows a comparison of the overall growth performance of several venerids in relation to latitude, a technique proposed by Pauly (1979) for both interspecific and intraspecific comparisons. The auximetric grid was obtained with data from the present study for E. paupercula and from other sources for the other venerid species: Callista umbonella (=Amiantis umbonela, Saeedi et al 2010), Eucallista purpurata (=Amiantis purpurata, Morsán and Orensanz 2004), Callista chione (Forster 1981;Metaxatos 2004;Ezgeta-Balić et al 2011), Circenita callipyga (Bagher et al 2007), Eurhomalea exalbida (Lomovasky et al 2002), Gafrarium pectinatum (=Gafrarium tumidum, Jagadis and Rajagopal 2007), Meretrix casta (Laxmilatha 2013), M. meretrix (Narasimham et al 1988), Protapes cor (=Paphia cor, Niamaimandi 2013), Ruditapes philippinarum (Chung et al 1994;Humphreys et al 2007;Ponurovskii 2008;Dang et al 2010;Colakoglu and Palaz 2014), Tivela mactroides (Arrieche and Prieto 2006;Turra et al 2014) and Leukoma antiqua (=Venus antiqua, Clasing et al 1994).…”