Reproductive biology ofUrotrygon microphthalmum(Batoidea: Urotrygonidae) from north-eastern Brazil, tropical west Atlantic Ocean

2016 ◽  
Vol 89 (1) ◽  
pp. 1026-1042 ◽  
Author(s):  
J. Santander-Neto ◽  
M. L. G. Araújo ◽  
R. P. Lessa
Author(s):  
Samara de P. Barros-Alves ◽  
Andréa Santos e Almeida ◽  
Ariádine Cristine de Almeida ◽  
Rogério Caetano da Costa ◽  
Douglas Fernandes Rodrigues Alves

AbstractLysmata vittata is considered an invasive shrimp in the Atlantic Ocean and some characteristics might have contributed to its invasive success, such as its larval nutritional vulnerability during the early stages of development. The objective of this study was to evaluate the early larval stages of the shrimp L. vittata. Ovigerous specimens were captured in an estuarine region of north-eastern Brazil. Zoeae were assigned to two experiments: (1) the point of no return (PNR), consisting of treatments with an increasing number of days of starvation and subsequent days of feeding; and (2) the point of reserve saturation (PRS), consisting of treatments with an increasing number of days of feeding and subsequent days of starvation. Two control groups were considered: continuous starvation (CS) and continuous feeding (CF). Nutritional vulnerability was estimated by the time when 50% of the initially starved larvae (PNR50) lost the ability to moult to the next stage, when 50% of the initially fed larvae (PRS50) were capable of moulting to the next stage. In the CF, the mean development time (±SD) of the larvae that reached stage III was 4.36 ± 0.74 days with a mortality of 70%, and the mean carapace length (±SD) was 0.61 ± 0.04 mm CL. The PNR50 and PRS50 were 2.42 ± 0.14 and 1.32 ± 0.83 days, respectively. The nutritional vulnerability index (PRS50/PNR50 = 0.54) indicates that L. vittata presents intermediate dependence on exogenous food during the early larval stages, which might help our understanding of the invasive potential of this species in the Atlantic Ocean.


2006 ◽  
Vol 21 (2) ◽  
pp. 85-91 ◽  
Author(s):  
ERIC CAMARGO SMIDT ◽  
VIVIANE SILVA-PEREIRA ◽  
EDUARDO LEITE BORBA

Author(s):  
M.L. Botter-Carvalho ◽  
L.B. Costa ◽  
L.L. Gomes ◽  
C.C.C. Clemente ◽  
P.V.V. Da C. Carvalho

The life history of the mud shrimpAxianassa australis, a common and widespread burrower inhabiting coastal mangroves and mud flats, is poorly known. This contribution presents the first information about the population structure, reproductive biology and fecundity ofA. australis, based on individuals collected from September 2011 to December 2012 on Casa Caiada Beach, located in a densely urbanized area in north-eastern Brazil, using a yabby pump. The sex ratio did not depart significantly from the expected 1:1 proportion. A significant trend of left-handedness of the major cheliped was observed in the population. Females reached a larger maximum cephalothorax length (CL) than males. The differential growth between CL and the propodus of the major cheliped showed negative allometric growth for females and positive allometric growth for males, suggesting a trade-off between somatic growth and reproductive effort. Females bearing uneyed orange embryos predominated during all months in which ovigerous females were collected. Mean fecundity was 2379 eggs, ranging from 5 (7.55 mm CL) to 8300 (14.19 mm CL) eggs per female. About 71% of the variation in the number of eggs carried per female was explained by CL. The mean egg size correlated negatively with fecundity, indicating that large females ofA. australisproduce more and larger eggs than smaller females.


Author(s):  
Joana Sandes ◽  
Ulisses Pinheiro

Clathria is one of the most species-rich genera among Demospongiae, but only nine species have been recorded so far from Brazil. Here we describe a new species of Clathria (Microciona) collected by trawling in waters of Sergipe State (north-eastern Brazil). The new species is differentiated from other encrusting Clathria with a hymedesmioid skeleton by the possession of a combination of long thin subectosomal subtylostyles, two category sizes of acanthostyles, both erect and echinating the basal spongin skeleton, long slightly curved choanosomal principal subtylostyles with tuberculate spine heads and wing-shaped toxas as microscleres.


Nature ◽  
1971 ◽  
Vol 232 (5306) ◽  
pp. 112-112 ◽  
Author(s):  
T. M. LEATHERLAND ◽  
J. D. BURTON ◽  
M. J. MCCARTNEY ◽  
F. CULKIN

2017 ◽  
Vol 98 (7) ◽  
pp. 1619-1644 ◽  
Author(s):  
Alexandre Dias Pimenta ◽  
Bruno Garcia Andrade ◽  
Ricardo Silva Absalão

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.


2001 ◽  
Vol 61 (4) ◽  
pp. 541-546 ◽  
Author(s):  
V. da BATISTA ◽  
N. N. FABRÉ

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles.


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