Morphological description of the first larval stages of the shrimps Lysmata ankeri Rhyne & Lin, 2006, L. bahia Rhyne & Lin, 2006 e L. lipkei Okuno & Fiedler, 2010 (Crustacea: Decapoda: Lysmatidae) with a revision of the morphology of the first larval stages of the genus

Author(s)

Andréa Santos e Almeida

• Document type: Master's Dissertation
• Press: Assis. 2020-04-02.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências e Letras. Assis
• Defense date: 2020-03-11
• Advisor: Rogério Caetano da Costa

Abstract

During thelarval phases, most decapod crustaceans are found in the planktonic region, showingmorphological characters distinctfrom the adults, which are commonly benthic. Carideansthe genus Lysmata Risso, 1816 areknown for the diversity of lifestylesand behavior, but there is still a lack of information about their early stages of life. Therefore, the present study aims to describe and illustrate the larval morphology of the initial stages of the species Lysmata ankeri, L. bahiaand L. lipkei, to make a review of the genus based on the larval morphology of the species that were previously described and to elaborate a identification key for the early stages of Lysmataspecies. The ovigerous femaleswere sampledin two estuarine regions in Aracaju -SE (L. lipkeiand L. bahia) and in Ilha das Couves, Ubatuba -SP (L. ankeri). Larvae from each larval stage were fixed and dissected under an optical stereomicroscope and illustrated with the aid of a microscope coupled to a lucid chamber. The larval morphology of the initial stages of the three species were compared with other species of the genus which were previously described. In total, five stages of L. ankeri species and three stages of L. bahia and L. lipkei were described. Several similarities were observed between the zoeas described here and also for those found in the literature, such as: eyes stalked from zoea II, with along peduncle; ventral margin of the carapace with spines; early development of the fifth pereiopod, with a flattened and paddle-like propodus with serrated margins; presence of dorso-lateral spines; among other features. Also, singularities were observed among the zoeas of each species described here. From the bibliographic review of the genus, singularities were found among the species belonging to the Lysmata subgroups, and it may be possible to visualize the formation of morphological patterns among the four natural clades of the genus, supporting the formed clades. Additionally, identification keys were elaborated for the first three zoeas of the genus. Studies with larval development are important to obtain information about the morphological diversity of species, phylogenetic relationships, larviculture and in addition to contribute to the identification of planktonic organisms and animals that are constantly commercialized in the ornamental market. (AU)

• FAPESP's process: 17/26792-1 - Larval development of the ornamental shrimps Lysmata ankeri, L. intermedia and L. bahia reared in laboratory (Crustacea: Decapoda: Lysmatidae)
• Grantee: Andréa Santos e Almeida
• Support Opportunities: Scholarships in Brazil - Master