Health Status Comparison of Blood Cockle (Tegillarca granosa) between Low and High Yield Farms in Selangor and Johor

This study aims to provide insight knowledge on the potential reason for low blood cockles (Tegillarca granosa) production in Sungai Buloh Selangor by comparing the condition indices and histology of the gills and gonad with samples from a high yield farm at Sungai Ayam, Johor. Samples were collected in September 2020 and grouped for histological analysis and for condition indices. About 60% individuals from Sungai Buloh and 20% of samples from Sungai Ayam found with degenerated gill filaments. The sex ratio were found identical (50%:50% male to a female) in samples from Sungai Ayam, while 40%: 60% of male to female from Sungai Buloh. The gonad of males found at Stage 2 (developing) and Stage 3 (developed or ripe) and the ovaries at Stage 3 and Stage 4 (spawning) for Sungai Buloh, and between Stage 2 to Stage 4 from Sungai Ayam. The total condition index (CI Tot) was significantly differences between farms. Findings indicate sample from Sungai Buloh has low health status due to poor gill’s filaments condition, and ripe ovaries found in lightweight (2 g) T. granosa. Hence being the potential reason for low survival rate in the Sungai Buloh.

Molecular Characterization and Expression of the LAP3 Gene and Its Association with Growth Traits in the Blood Clam Tegillarca granosa

Leucine aminopeptidase 3 (LAP3) is a metallopeptidase that cleaves N-terminal residues and is involved in protein maturation and degradation. In this study, we characterized the leucine aminopeptidase 3 (LAP3) gene from Tegillarca granosa (Tg-LAP3 for short), which appeared to consist of 15,731 nucleotides encoding 530 amino acids. We identified 12 introns and 13 exons in the Tg-LAP3 gene, suggesting a highly conserved genomic structure. The proximal promoter sequence consists of 1922 bps with a typical TATA box structure, which is the general structural characteristic of core promoters in eukaryotes. We found two functional domains in the Tg-LAP3 protein, including an N-terminal domain (41–174aa) and a peptidase_M17 catalytic domain (209–522aa). Multiple alignment showed that Tg-LAP3 shares 73.4% identity with LAP3 of Mizuhopecten yessoensis and 55.2–70.7% identity with LAP3 of other species. Quantitative analysis of Tg-LAP3 in embryos/larvae and adult tissues indicated that the highest expression occurred in eyebot larva, with limited expression in other stages; among tissues, the highest expression was found in the liver (p < 0.05). Association analysis found that three single-nucleotide polymorphisms (SNPs) (g.-488A > G, g.-1123C > T, and g.-1304C > A) in the proximal promoter were successfully typed, but there was no significant difference in growth traits (body weight, shell length, shell width, and shell height) among these genotypes. The results of our study demonstrate the functional roles of the Tg-LAP3 gene and provide valuable information for molecular marker-assisted selection (MAS) of the blood clam.

Kondisi Biometrik Kerang Darah, Tegillarca granosa, di Pesisir Pantai Utara Kota Banda Aceh

The blood clam, Tegillarca granosa (Linnaeus, 1758) is one of the economically important aquatic organisms. Therefore, information related to biometric conditions is crucial as preventive and responsive efforts to manage blood clams. This study aims to analyze the biometric condition of blood clams collected from the northern coast of Banda Aceh City. Blood-clam samples were collected from three locations, namely Alue Naga, Tibang, and Deah Raya. A total of 300 blood clams were observed. The biometric parameters included the distribution of length and weight classes, the relationship between length and weight, condition factors, ratios, and correlations between total weight, meat weight, and shell weight were measured. The results showed that the majority of blood clams found in Deah Raya were in the smaller length and weight classes (30-32 mm and 12,25-17,24 g) compared to those found in Alue Naga (33-35 mm and 17,25-22,24 g) and Tibang (42-44 mm and 22,25-27,24 g). Despite having identical growth patterns (negative allometric) and condition-factor values, the blood clams collected from Alue Naga had higher meat weight ratios than those collected from the other two locations. The correlation values between the weight of the meat and the total weight of the blood clams collected from Deah Raya tends to be lower than those of blood clams obtained from Alue Naga and Tibang, which are 0,55; 0,81; and 0,78, respectively. Keywords: biometric, environmental factor, Deah Raya