Abstract
Pacific oyster (Crassostrea gigas) is an invasive species which is able to adapt a wide range of environmental conditions. The study was conducted from August to October 2014. Objective of this study was to asses the distribution pattern, condition and gonad maturity length (Lm 50%) of the Pacific oysters in mangrove ecosystem of Cimanuk Delta, Indramayu, West Java, Indonesia. This study was conducted in two adjacent areas: Pabean Ilir and Pagirikan subdeltas. The oysters were collected from the estuary, brackish water ponds and the coastal flat, and observed for their abundance, total length (mm) and weight (g). Morphological and histological methods were used to estimate the gonad maturity stage. Analysis were carried out to estimate distribution pattern and condition factor. According to the study, the Pacific oyster distribution pattern was clumped. The condition factor of the oyster was higher in the brackish water pond and estuary than in the coastal flat. The Pacific oyster was found in gonad maturity stage (GMS) I – IV. The oyster was hermaprodit protandry and had length maturity (Lm 50%) of 47,46-48,43 mm (male) and 75,27-75,50 mm (female).
Highlights
Pacific oyster (Crassostrea gigas) is one of the important fishery resources in Indramayu waters
From the graph of the length frequency distribution of the Pacific oysters in Pabean Ilir (Figure 3), it can be seen that in August the size of the oyster from the sampling was at the class interval of 26 to 75 mm with the highest frequency occurred in the class interval of 46-55 mm
The results of the analysis shows that the two locations in Cimanuk Delta, namely, Pabean Ilir and Pagirikan Subdeltas, have the biggest condition factor in the habitats of brackish water ponds and estuaries while at the coastal flat has the smallest condition factor
Summary
Pacific oyster (Crassostrea gigas) is one of the important fishery resources in Indramayu waters. Habitat of the oyster is generally found in the estuary (Kennedy, 1996), as well as in Pabean Ilir and Pagirikan Subdeltas in the Cimanuk Delta which are estuarine waters with mangrove vegetation. The mangrove ecosystem has an ecological function in maintaining the existence of the environment such as preventing the intrusion of sea water (Widiastuti, 1998), inhibiting the occurrence of abrasion, trapping sediment and providing food. River water which carries the inorganic particles will enter the aquatic ecosystem and cause to coastal area to become turbid (Riani, 2012). Such condition can disrupt aquatic biota that can cause changes in population dynamics (Powell et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
