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Characterizing the Norway Lobster Nephrops norvegicus (L., Homarida: Decapoda) Maturity of Males in the Mediterranean Sea: Morphological and Physiological Aspects
by
, , , , , and
Cristina Porcu
1,*,†
,
Noemi Pascale
2,3,*,†,
Andrea Bellodi
1,4
,
Pierluigi Carbonara
5
,
Alessandro Cau
1,
Riccardo Demurtas
1,6,
Antonello Mulas
1 and
Maria Cristina Follesa
1
1
Department of Life and Environmental Sciences, University of Cagliari, Via T. Fiorelli 1, 09126 Cagliari, Italy
2
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
3
Department of Biomedical Sciences, University of Sassari, Via San Pietro 43/b, 07100 Sassari, Italy
4
Department of Integrated Marine Ecology, Calabria Marine Center, Stazione Zoologica Anton Dohrn (SZN), C.da Torre Spaccata, Località Torre Spaccata, 87071 Amendolara, Italy
5
Fondazione COISPA, Via Trulli, 18-20, 70126 Bari, Italy
6
CoNISMa Consorzio Nazionale Interuniversitario per le Scienze Mare, Piazzale Flaminio 9, 00196 Rome, Italy
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Animals 2025, 15(23), 3478; https://doi.org/10.3390/ani15233478 (registering DOI)
Submission received: 3 October 2025
/
Revised: 21 November 2025
/
Accepted: 27 November 2025
/
Published: 2 December 2025
(This article belongs to the Section Aquatic Animals)
Simple Summary
This study analyses the maturity for male Norway lobsters in Sardinian waters, focusing on primary sexual characteristics and morphometric traits. The aim was to understand the timing of maturity for better fisheries management. Results revealed that spermatogenesis occurs year-round, with the smallest mature individual at 18.3 mm carapace length (CL). Physiological maturity was reached in males over 23.5 mm CL, while morphometric maturity occurred between 27.7 and 36.2 mm CL, based on appendix masculina and petasma size. The study found that secondary sexual characteristic development and physiological maturity are not always synchronous. These findings have important implications for sustainable management of this commercially exploited species, as they offer insights into reproductive success and population dynamics.
Abstract
In male decapods, such as the Norway lobster Nephrops norvegicus, sexual maturity is not easily determined by macroscopic examination of gonads and few studies have been conducted on this topic. Sexual maturity is linked to changes in both external morphology and physiology. This study analyzed the maturity of N. norvegicus males in the Central-Western Mediterranean Sea (Sardinia), focusing on primary sexual characteristics (testes and vasa deferentia) and morphometric traits (appendix masculina and petasma). Since the testes showed no macroscopic changes in size during ontogeny, histological analysis was performed. It revealed that spermatogenesis occurred year-round in the Sardinian population, with the smallest mature individual at 18.3 mm carapace length (CL). All individuals above 23.5 mm CL had testes and vasa deferentia filled with spermatozoa and were considered physiologically mature. Morphometric maturity was observed between 27.7 and 36.2 mm CL, based on appendix masculina and petasma measurements. Despite a close association, secondary sexual characteristic development and physiological maturity were not synchronized, as seen in other crustaceans. This discrepancy likely reflects differences in male reproductive strategies, as males may produce spermatophores at smaller sizes (e.g., 23.5 mm CL), though there is no evidence that such males can successfully inseminate females in the wild.
