Variación estacional de la actividad reproductiva y de la composición bioquímica de ostra plana (Ostrea edulis) en Homa Lagoon, bahía de Izmir, Turquía

The reproductive cycle of the flat oyster, Ostrea edulis Linnaeus, 1758, in Homa Lagoon, Izmir Bay, Turkey was examined from August 2008 to July 2009. Gonad samples were analysed histologically in order to determine the sex ratio and gonad development stage. Overall, the sex ratio was recorded as 2.2% female, 42.6% male, 37% hermaphrodite and 17.9% inactive. Glycogen content showed considerable variations between August and February, but decreased gradually thereafter. However, glycogen did not directly affect the reproductive cycle. Total lipid content was positively correlated with temperature and inversely correlated with salinity. In addition, this parameter was influenced by the reproductive activity, which is correlated with the fluctuation of the condition index and gonad index (P < 0.05). However, the relationship between the protein index and the gonad index was negative (P < 0.05). The results of this study showed that protein was the major energy resource. The condition index varied between 2.69±0.91 (February) and 12.29±1.45 (April) during the year. With respect to meat yield, oyster quality changed from “fine” to “special”, except in December and February.El ciclo reproductivo de la ostra plana, Ostrea edulis Linnaeus, 1758, en Homa Lagoon, Bahía de Izmir, Turquía, fue examinado entre agosto de 2008 y julio de 2009. Las gónadas se analizaron histológicamente para determinar la proporción de sexos y su estado de desarrollo. La proporción de sexos encontrada fue 2.2% hembras, 42.6% machos, 37% hermafroditas y 17.9% inactivos. El contenido de glucógeno mostró considerables variaciones entre agosto y febrero, pero después de estos meses se produjo un aumento gradual. Sin embargo el glucógeno no afectó directamente el ciclo reproductivo. El contenido total de lípidos se correlacionó positivamente con la temperatura e inversamente con la salinidad. Además, este parámetro estuvo influenciado por la actividad reproductiva, que se correlaciona con la fluctuación del índice de condición y del índice gonadal (P < 0,05). Sin embargo la relación entre el índice de proteína y el índice gonadal fue negativa (P < 0,05). Los resultados de este estudio mostraron que la proteína era la principal fuente de energía. El índice de condición varió entre 2.69±0.91 (febrero) y 12.29±1.45 (abril) durante el año. En lo que respecta a la producción de carne, la calidad de las ostras pasó de “fine” to “special”, excepto en diciembre y febrero

Preliminary study of settlement of flat oyster spat (Ostreaedulis L.) on oyster and mussel shell collectors

Oyster recruitment was monitored in Karantina Island near Izmir, Turkey, from May to October 1999. The aim of the study was to determine the recruitment pattern for six months and the most suitable time to collect oyster spat from nature. Oyster and mussel shells were used as sub- strates in spat collectors. Five groups of each type of collector were deployed from May to August. The recruitment levels were highest in the groups deployed on June 16, with 4069 and 1575 oyster spats collected on the oyster and mussel shell collectors, respectively. Spat recruit- ment varied considerably between collector types as well as between the outsides and insides of shells (p<0.05). Spats larger than 10 mm were found on the second or third sampling date in each group for both oyster and mussel shell collectors. Barnacles (Balanus sp.) settled on both collector types in high numbers throughout the study. Data suggest that maximum recruitment in this area is most likely to occur on both collector types between May and mid-June

Larvae Development Stages of the European Flat Oyster (Ostrea edulis)

This paper reports on the larvae development of the flat oyster, Ostrea edulis (Linnaeus, 1758), from veliger to pediveliger stage. Adult oysters were induced to spawn by thermal stimulation and large amounts of veliger larvae were obtained for study. Veliger larvae were cultured in 180-l bins at a den- sity of 3 larvae/ml. Larvae, reared at 20±2°C and fed 8-200 x 103 cells/ml of Isochrysis galbana, reached pediveliger larvae in 17 days. Shell length and width at the beginning of the pediveliger stage were 254 and 233 μm, respec- tively. Survival rate from veliger to viable pediveliger stage was 15.5%

Growth and Survival of Anadara inaequivalvis (Bruguiere, 1789) in Sufa Lagoon, Izmir, Turkey

The growth and survival of 5, 7, 9, and 11-mm juvenile blood cockle (Anadara inaequivalvis) cultured in suspended nets in Sufa Lagoon, Izmir, Turkey, were investigated. Shell length, width, and thickness and total weight were measured monthly during May 2007-May 2008. Temperature was measured every 6 h. Salinity, chlorophyll a, particulate organic matter, particulate inorganic matter, and total particulate matter were followed every two weeks. Mean increases were 16.68 and 13.46 mm and 3.62 and 5.74 g for small and large spat, respectively. Length increased significantly faster in small cockle than in large cockle (p<0.05). Survival was 65% and 100% in small and large cockles, respectively (p<0.05). Von Bertalanffy growth parameters L∞ (27 mm) and k (0.28/month) showed that growth performance (Ф′ = 3.22) was greater than for other species in the natural population. Slope b from the length-weight relationship was 3.098±0.115, indicating significantly better allometric growth (p≤0.05). Results indicate that A. inaequivalvis is a good candidate for suspended aquaculture in the Sufa Lagoon, Turkey

Comparison of Isochrysis galbana and Chlorella sp microalgae on growth and survival rate of European flat oyster (Ostrea edulis, Linnaeus 1758) larvae

WOS: 000291625200008Influence of microalgal feeding with Isochrysis galbana and Chlorella sp. on the growth and survival rate of larvae of European flat oyster, Ostrea edulis, was investigated. Larvae were reared with four food regimes: I. galbana, Chlorella sp., mixture of both and unfed for 16 days. After 16 days, it was observed that the larvae reached the umbo stage with a mean size in length 220 +/- 4.12 mu m and 219 +/- 5.76 mu m (initial length, 159 mu m) (P>0.05). Larvae were fed on I. galbana and mixture diet. At this stage, survival rate was 30% and 24%, respectively (P>0.05). Growth and survival rates for the feeding regimes were significantly higher than the Chlorella sp. and unfed groups (P<0.05)

Association Between The Crab, Nepinnotheres pinnotheres (Linnaeus, 1758), and The Endangered Species Fan Mussel, Pinna Nobilis (Linnaeus, 1758), from The Aegean Sea, Turkey

Pinna nobilis, commonly known as the fan mussel or pen shell, is an endemic species in the Mediterranean Sea. The fan mussel population has recently been significantly endangered along the Mediterranean coast, mainly due to diseases. However, it has a critical role in the ecological system of the throughout the coasts of the Mediterranean. Therefore, it is important to investigate the interactions between P. nobilis and their enemies, parasites, symbiont in the ecological environment. Pea crabs are small crustacean and symbionts in a variety of invertebrates. They inhabit the mantle cavities of bivalve. The association between the pea crab, Nepinnotheres pinnotheres ( Decapoda), and P. nobilis (Bivalvia) from the Aegean Sea, Turkey was examined in this study. The crab samples were collected off Urla Karantina Island, Izmir Bay, Aegean Sea. The biometric characteristics of bivalve and crab in this coexistence were analyzed. 80% of P. nobilis was occupied by N. pinnotheres. The weight of pea crabs was recorded between 0.01 g and 3.87 g

Culture of Fan Mussel (Pinna nobilis, Linnaeus 1758) in Relation to Size on Suspended Culture System in Izmir Bay, Aegean Sea, Turkey

WOS: 000298308700018The growth and survival of fan mussel (Pinna nobilis, Linnaeus) juveniles, from natural spatfall, were compared in two groups (large and small size) in Karantina Island Izmir, Turkey, between December 2004 and April 2006. Total live weight, shell length, width and thickness of fan mussel were measured monthly during the study period. Small (32 mm) and large (73 mm) size groups of fan mussel individuals reached 140.25 +/- 10.46 mm and 154.36 +/- 16.12 mm in length and 64.64 +/- 17.98 g and 99.74 +/- 30.53 g in live weight, respectively. Significant differences were found in increases of shell length and live weight. Environmental parameters such as chlorophyll-a, seawater temperature, salinity, particulate organic matter (POM) and particulate inorganic matter (PIM) were determined during each sampling period. Shell length increase was affected by chlorophyll-a and PIM. However, increases in shell length did not correlate with temperature and POM. Survival rates for small and large groups were 93% and 100%, respectively