Length - Weight Relationship and Condition Factor of Daisy Stingray, Fontitrygon margarita off Lagos Coastal Waters, Nigeria

The daisy stingray, Fontitrygon margarita, is a West African coastal species declining due to overfishing and habitat loss. A study of the length-weight relationship (LWR) and condition factor of the daisy stingray, Fontitrygon margarita, was conducted using data from six landing sites in the coastal areas of Lagos State, Nigeria. A total of 1012 specimens of Fontitrygon margarita used for this study were collected from the landing sites of local fishermen (monthly) from February 2023 to July 2024. The disc width of each specimen was measured to the nearest centimeter using a tape, and the weight was measured to the nearest gram on a digital balance. The linear regression equation for females, males, and combined sexes using log-transformed disc width-weight relationship revealed a positive allometric growth (b>3) for all the sexes. The condition factor analysis of F. margarita ranged from 3.09 to 4.47 for the female, 3.24 to 3.97 for the male, and 3.20 to 4.47 for the combined sexes. The highest k values were observed in larger size classes 27.5-29.4, 31.5-33.4 for the female, male, and combined sexes, respectively. The lowest K value (3.09) was recorded in size class 17.5-19.4 for the female. The increase in weight with disk width follows a positive allometric growth pattern, with larger individuals exhibiting superior condition, possibly due to enhanced feeding efficiency and reproductive maturity. These findings provide baseline data for stock assessment, conservation, and development of sustainable management strategies for F. margarita in Nigerian coastal ecosystems.