Biometric Characteristics of the Siboga Squid Uroteuthis (photololigo) Sibogae (Adam, 1954) from the South East Coast of India

Abstract

Objectives: To study the various linear and non-linear relationships among the variables of siboga squid Uroteuthis (photololigo) sibogae (Adam, 1954) from the South East Coast of India from August to November 2021. Methods: Samples of the siboga squid were measured to the nearest value of 1.0mm and the weight was measured to 1gm. Findings: Females had a mean DML of 120 mm, whereas males were 129 mm. The mean total weight of pooled sexes was 38.9 gm with the female being 35.9 gm and the male 41.8 gm. Regarding mean mantle weight, the female was 20.5gm and the male was 24.7 gm with pooled sex of 22.6 gm. The nonlinear relationship between length and the total weight of females was calculated as 0.0014x2.1119, while the male was calculated as 0.0009x2.1998 and the pooled sex as 0.0009x2.2075. Whereas, the length-Mantle weight relationship of females and males was calculated as 0.0015x1.9857, 0.0004x2.2663 respectively, with pooled one as 0.0006x2.1721. The length - total weight and length - mantle weight relationship of female, male, and pooled sex shows negative allometric (b<3) indicating less cuboidal growth. Similarly, the linear morphometric relationship of female, male, and pooled sex also showed negative allometric growth (b<1). The P-value of b shows high significance (P<0.05), which rejects the null hypothesis. Novelty: The study on length-weight and the morphometric relationship of the species to understand the difference in growth patterns between males and females. Keywords: Uroteuthis (photololigo) sibogae; lengthweight relationship; morphometric study; allometry growth; sexual dimorphism