Male reproductive systems of Macrobrachium pantanalense Dos Santos, Hayd & Anger, 2013 and M. amazonicum (Heller, 1862) (Decapoda: Caridea: Palaemonidae): new insights into the morphology of the spermatozoa of decapod crustaceans

Author(s)

Nogueira, Caio S. ; Zara, Fernando J. ; Costa, Rogerio C.

• Document type: Journal article
• Source: JOURNAL OF CRUSTACEAN BIOLOGY; v. 45, n. 1, p. 20-pg., 2025-02-11.

Abstract

Studies on the male reproductive system (MRS) and the ultrastructure of spermatozoa may provide key information about the reproductive biology and phylogenetic relationships between crustacean species. We describe the functional anatomy of the MRS and the ultrastructure and morphometry of spermatozoa of two closely related freshwater shrimps, Macrobrachium pantanalense Dos Santos, Hayd & Anger, 2013 (MP) and M. amazonicum (Heller, 1862) (MA) to detect possible interspecific differences. We introduce geometric morphometrics as a new tool to analyze the caridean spermatozoa for closely related species. The main differences in the anatomy of the MRS of the two species are related to the positive reaction to acid polysaccharides in the distal region of the vas deferens of M. pantanalense and the shape and size of their spermatozoa. SEM and TEM analyses confirmed variations in the shape of spermatozoa of both species and this variation was found to be significant by the use of geometric morphometrics. These tools can highlight differences among caridean shrimps, mainly in cases of closely related species. It becomes clear that MA and MP, despite being two closely related taxa that evolved separately relatively recently, are distinctly different taxa with differences found mainly in the spermatozoa. (AU)

• FAPESP's process: 18/13685-5 - Integrative analysis of the Brazilian fauna of decapod crustaceans: taxonomy, phylogenetic systematics, spermiotaxonomy, morphology of post-embryonic development, ecology and conservation
• Grantee: Fernando Luis Medina Mantelatto
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 19/00661-3 - A comparative interdisciplinary analysis between the prawns Macrobrachium amazonicum (Heller, 1862) and Macrobrachium pantanalense (dos Santos, Hayd & anger, 2013) support the interspecific differentiation?
• Grantee: Caio dos Santos Nogueira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 23/01445-8 - Ultrastructure of spermatozoa of the caridean shrimps of Brazil: a modern taxonomic approach through morphological and phylogenetic integration
• Grantee: Caio dos Santos Nogueira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral