Redescription of the larval stages of the freshwater shrimp Macrobrachium amazonicum (Heller, 1862) and Macrobrachium pantanalense Dos Santos, Hayd & Anger, 2013 (Caridea, Palaemonidae) under laboratory conditions.

• Grant number: 24/10619-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2025
• End date: March 31, 2026
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Rogério Caetano da Costa
• Grantee: Matheus Sene Oliveira
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated research grant: 18/13685-5 - Integrative analysis of the Brazilian fauna of decapod crustaceans: taxonomy, phylogenetic systematics, spermiotaxonomy, morphology of post-embryonic development, ecology and conservation, AP.BTA.TEM

Abstract

Macrobrachium Spence Bate, 1868 includes large species of freshwater and estuarine shrimp, with approximately 267 described species, of which 21 have reported occurrences in Brazil. Until recently, there was uncertainty about the taxonomic status of Macrobrachium amazonicum (Heller, 1862) and Macrobrachium pantanalense Dos Santos, Hayd & Anger, 2013, with M. pantanalense considered a synonym of M. amazonicum. Although M. amazonicum and M. pantanalense have complete larval descriptions (Zoea I to juvenile), morphological variations have been reported for the descriptions of both species, and there is also a lack of illustrations and descriptions in certain appendages. In this regard, considering the taxonomic problems involving M. amazonicum and M. pantanalense and the incongruences in larval morphology, this project aims to redescribe the complete larval development of M. amazonicum and M. pantanalense and compare the available original descriptions. To this end, ovigerous females of the amphidromous population of M. amazonicum were obtained through the Shrimp Farming Sector of the Aquaculture Center (CAUNESP) at the São Paulo State University "Júlio de Mesquita Filho" (UNESP), located in the municipality of Jaboticabal, state of São Paulo, Brazil. For M. pantanalense, sampling was carried out in its type locality, in Lagoa da Baiazinha, located in the municipality of Miranda, Mato Grosso do Sul, Brazil (20°15'49'' S; 56°23'15'' W).