Reproductive Biology and Gross Biochemical Composition of Larkinia grandis (Bivalvia: Arcidae) in the Northwestern of the Mexican Pacific

The reproductive cycle of Larkinia grandis (Broderip and G.B. Sowerby I, 1829) from the NW Mexican Pacific was analyzed in relation to environmental variables, condition index (CI), and biochemical composition of different tissues. A total of 960 clams (80/month; 44.5–142.0 mm, shell height) were collected from the El Cohui estuary in the Navachiste lagoon, Sinaloa, Mexico (NW of the Mexican Pacific), during an annual cycle (August 2017 to July 2018). The species exhibited a semiannual reproductive pattern with two spawning peaks (October–December 2017 and April–July 2018). Reproductive activity was strongly correlated with temperature ( r p = 0.73, p = 0.02), salinity ( r p = 0.73, p = 0.02), and food availability (Chl‐ a ) ( r p = 0.70, p = 0.03). The CI (35.93 ± 8.34−62.29 ± 6.96) reflected gonadal maturity ( r p = 0.73, p = 0.02), while biochemical analyses revealed lipids as the main energy reserve, followed by proteins, triglycerides, and carbohydrates (281.64 ± 107.74, 148.49 ± 74.27, 140.57 ± 37.78, and 46.65 ± 6.33 mg g −1 , respectively). Energy mobilization from mantle, adductor muscle, and digestive gland to the gonad was evident during gametogenesis. These findings provide essential knowledge for the management, conservation, and aquaculture of this arcid clam.