Karakter morfometri kerang kepah Polymesoda erosa dari dua jenis vegetasi mangrove (Avicennia marina dan Rhizopora apiculata)

Abstract

Morphometry information on mud clam Polymesoda erosa in mangrove ecosystem is very important for sustainability of biodiversity conservation. This study purpose was to determine morphometry characters of mud clam (Polymesoda erosa) from two types of mangroves vegetation that commonly found, ie : Avicennia marina in Pagatan Besar Village and Rhizopora apiculata in Tabanio Village. Sampling uses a purposive method with three plots in different vegetation. Data were analyzed descriptively, then mud clam morphometry difference were tested using paired sampled t-test. Morphometric observations showed that the weight, length, height, and width of shell from Avicennia marina were higher than Rhizopora apiculata, except for meat weight. In Avicennia marina, shell weight was ± 20.70 grams and meat weight ± 3.89 grams, while length of the shell : height of the shell and width of the shell lies in the range of ± 41.33 mm: ± 24.88 mm and ± 34.6 mm. For Rhizopora apiculata, shell weight and  meat weight at the range of ± 20.70 grams and ± 5.17 grams, then comparation of shell length : shell height and shell width is ± 41.33 mm: ± 24.88 mm: and ± 34.6 mm. Results test comparation showed that only meat weight parameter was significantly different (p = 0,000). Four color patterns were found in the shells of mud clam, ie : black, orange, black cream and plain cream. Black cream color pattern was found more than the other colors (69.9% from Avicennia marina and 51.5%. The mean value of the water parameters from Avicennia marina, such as temperature was 29 0C, salinity 5 o/oo and pH was 6.8 while from Rhizopora apiculata the average temperature reached 30 0C, salinity 15 o/oo and pH was 6.9. The substrate content (sand : dust : clay) from Avicennia marina is 4 % : 85 % : 11 % while from Rhizopora apiculata the sand content is 11 %, 80% of dust and 9% of clay. Common conclusions that the morphometric parameters, especially meat weight and color patterns of mud clam shells is differ from the two types of mangrove vegetation compared.