Size Composition of Hexaplex (Muricanthus) nigritus (Mollusca: Muricidae) in the Intertidal Zone of Five Islands of the Southeastern Gulf of California, Mexico.

Background: Currently, there is no fishery regulation for Hexaplex (Muricanthus) nigritus in northwestern Mexico. The size composition of gastropod H. nigritus was recorded from five islands of Navachiste Bay, Sinaloa (Gulf of California, Mexico). Methods: Samples were taken every two months from February to December 2018. Islands established a georeferenced GPS station: Guasayeye, La Huitussera, Tesobiate, El Metate and San Lucas, Sinaloa, Mexico. The snail H. nigritus was collected in the littoral zone of the islands during the low tide syzygy tides. The organisms were collected directly at random and the total length (TL), width (WI) and height (HI) (0.01 mm) and total fresh weight (W) and muscle foot weight (FW) (0.1 g sensitivity). In addition, the shape of the growth was estimated with the equation that describes the relationship between length and weight. Result: The island of Guasayeye was a greater abundance (48%) and the least La Huitussera (4%). The mean total length (TL) was greater in San Lucas and La Huitussera (99.5±7.2 and 95.1±15.5 mm, respectively) and lower values were recorded in Tesobiate (73.8±11.4 mm). The maximum weight recorded was 347.2 g on El Metate island. A significance in length and weight were obtained between the islands. In addition, in H. nigritus high correlations were obtained relationships, indicating positive allometric growth. For their sizes and abundance, the snail H. nigritus is a potentially interesting fishing resource for the fishers of northwestern Mexico. [ABSTRACT FROM AUTHOR]