Ontogenetic changes in morphometry of the spiny lobster, Panulirus homarus homarus (Linnaeus, 1758) from southern Indian coast

Abstract

The morphometric relationships, carapace length vs total length (CL vs TL), carapace length vs weight (CL vs W), total length vs weight (TL vs W), carapace length vs carapace width (CL vs CW), carapace length vs length of third walking leg (CL vs III WL) and carapace length vs width of second abdomen (CL vs II ASW) were estimated for the Scalloped spiny lobster Panulirus homarus homarus fished from east and west coast of Tamilnadu. A total of 462 males and 350 females were measured for the study. Carapace length of lobsters ranged from 20.4 mm to 101.0 mm CL. The power function y=ax b was applied in all the relationships. The first derivative dY/dCL-abCL b-1 where Y is TL was used to study the growth tendency of TL in relation to CL. A negative allometry, b<1 was found for males which was also reflected in their decreasing growth rate of TL in relation to CL. The CL vs W relationship showed a general negative allometry, b<3 in both sexes. Size at the onset of sexual maturity in male was determined based on allometric growth of third pereopod. Slopes of regression of log transformed data showed positive allometric growth of third pereopod for males (b=1.17) compared to negative allometry in females (b=0.97). Females had (b=1.04) positive allometry in second abdomen width compared to negative allometry in males (b=0.934). However, their size at maturity could not be precisely predicted as the b value of the two regression lines of immature (1.09) and mature females (1.01) did not indicate any significant deviation from 1. The size at maturity of males (63.0 mm) was determined where the two regression lines of mature and immature specimens crossed. The results obtained in the present study support the predictions of resource allocation theory in crustaceans and demonstrate marked shifts in resource allocation through ontogeny in both sexes.

Population Characteristics of the European Lobster, Homarus gammarus in the Adriatic Sea: Implications for Sustainable Fisheries Management

“…Comparing the slopes of the ordinary least-square regressions, we observed significant differences of all relationships between males and females, indicating different growth rates by sex [38,86]. The negative allometry, i.e., a decreasing growth rate of TL vs. CL and CL vs. W for both sexes, reflects a morphological change from an elongated body towards a heavier one, as also reported by Martínez-Calderón et al [34] for the Caribbean spiny lobster (Panulirus argus) and Radhakrishnan et al [87] for Panulirus homarus. French McCay et al [84] reported a coefficient b of 2.934 for an American lobster population, which is similar to our results that gave a coefficient b below 3 for both sexes, while Steinback et al [85] reported a coefficient b of 3.347 for males and 2.972 for females for American lobster.…”

Influence of pseudo-green water on growth, colouration, and survival in European lobster (Homarus gammarus) larvae

“…Nannochloropsis salina, which contains a high level of the PUFA eicosapentaenoic acid (EPA; 20:5n-3), has been shown to improve growth performance and survival in the phyllosoma larvae of the tropical spiny lobster ( Panulirus homarus ) (Radhakrishnan et al, 2009). Results were attributed to improved water quality and enhanced Artemia enrichment through constant feeding on N. salina .…”