Banca de DEFESA: NIRLEI HIRACHY COSTA BARROS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : NIRLEI HIRACHY COSTA BARROS
DATA : 12/07/2016
HORA: 09:00
LOCAL: Sala de Reunião do Departamento de Oceanografia e Limnologia
TÍTULO:

Strategy of sex reversal in the marbled swamp eel, Synbranchus marmoratus (Osteichthyes: Synbranchidae) a hermaphrodite, protogynous and diandric fish of Rio Grande do Norte, Brazil

PALAVRAS-CHAVES:

S. marmoratus, sequential hermaphrodite, gonadal histology, otoliths, reproductive strategy.

PÁGINAS: 200
GRANDE ÁREA: Ciências Humanas
ÁREA: Psicologia
RESUMO:

Reproductive strategy of the hermaphroditic fish, the marbled swamp eel, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) was verified, with individuals captured from July, 2011 to October, 2013, from two hydrographic basins of Rio Grande do Norte, Brazil. The following aspects of the study species were verified, morphometric measurements, taxonomy, sex ratio, length-weight relationship, body size at first sexual maturity (L₅₀), gonadal development stages, gonadosomatic index (GSI), the condition factor (K), hepatosomatic index (HSI), fecundity and the reproductive period, besides the environmental variables and otolith analyses. The data obtained from the results of this research are presented in the form of six articles, one book chapter  and four international abstracts. The first article deals with the reproductive biology of S. marmoratus, which confirmed four different sexual types of individuals in the sampled population, and characterized the species as a protogynic hermaphrodite with diandria. The second article presents the seasonal changes of the condition factor, gonadosomatic and hepatosomatic indices of S. marmoratus during an annual period. The growth was negatively allometric and the reproductive period was during July and August, when theGSI had its peak values.The third article explains about the equilibrium strategy (K) adapted by S. marmoratus. The fourth article describes the histological aspects of gonad development during sex reversal of S. marmoratus. The fifth article presents and compares the reproductive strategies adapted by six fish species including S. marmoratus of the semi-arid region. S. marmoratus presentes equilibrium strategy with low fecundity and total spawning. The sixth article indicates that sex reversal ocourrs in females at a mean age of five and six years based on otolith studies. The book chapter is based on sex change dynamics of S. marmoratus females, showing that the transitional individuals presented both ovarian and testicular tissues in their gonads.  The four international abstracts depict the temporal dynamics of reproduction of the neotropical fish S. marmoratus, including the sex ratio, length-weight relationship, body size at first sexual maturity, K, GSI, HSI, L₅₀ and fecundity.  S. marmoratus is a sequential hermaphroditic species, exhibiting protogyny, and diandry, presenting an equilibrium reproductive strategy. This strategy renders the species well adapted to the semi-arid region.

MEMBROS DA BANCA:
Externo ao Programa - 348087 - GRACO AURELIO CAMARA DE MELO VIANA
Externo à Instituição - JOSÉ ZANON DE OLIVEIRA PASSAVANTE - UFPE
Externo à Instituição - LILIANE DE LIMA GURGEL - IFRN
Externo ao Programa - 2477216 - NAISANDRA BEZERRA DA SILVA FARIAS
Presidente - 346769 - SATHYABAMA CHELLAPPA