Length–Weight and Condition Factor of 14 Elasmobranch Species Caught as Bycatch by Artisanal Shrimp Trawls in a Coastal Lagoon System From Northwest Mexico
Year: 2026
Type: article
Abstract: The lack of biometric data on chondrichthyan species has impeded the implementation of management strategies essential for the conservation of sharks and rays captured using different fishing gears in coastal ecosystems. This study aims to assess morphometric relationships (length–weight [LW], length–dorsal length [DL], and length–disc width [DW]) and the relative weight condition factor ( K rel ) of 14 elasmobranch species caught by shrimp trawls in the Bahía Magdalena‐Almejas (BMA) lagoon system in Mexico from February to December 2014–2022. The length–weight relationships (LWRs) (pooled sexes, females and males) were calculated using the potential model. The growth (allometric or isometric) was determined by comparing the b values for each elasmobranch species with the isometric value ( b = 3.0) using the t ‐Student test. Length–length (LL) relationships were determined by applying the linear regression model. Given the body condition is commonly used as a biometric tool to indicate the overall health and energetic status of fish in relation to growth, the K rel was calculated. The assessment was conducted on 440 elasmobranch specimens (70 sharks and 370 rays) across 14 species, 9 genera, and 8 families. The genus Urobatis was the most abundant in the total elasmobranch catches obtained ( n = 203). The parameter b of the LW relationships varied from 2.57 ( Heterodontus mexicanus ) to 3.87 ( Mustelus lunulatus ). Most morphometric relationships (LDL and LDW) showed a significant statistical correlation ( r 2 > 0.85; p < 0.05). The condition factor analysis indicated that most (86%) elasmobranch species were in good somatic condition ( K rel ≥ 1). This study represents the first reference data on the LWRs for the Mexican Horn Shark ( H. mexicanus ), as well as the first assessment on LL relationships (DL and DW) and the relative weight condition factor for all elasmobranch species included. Consequently, this research helps bridge the information gap regarding shark and ray species, contributing to the monitoring and population assessment of bycatch elasmobranchs in the BMA lagoon system.
Source: Journal of Applied Ichthyology
DOI: 10.1155/jai/7165553
Language: English
Subfield: Nature and Landscape Conservation
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: hybrid
Estimated APC paid: $2,430
OpenAlex ID: W7134166209