Mario Katsuragawa

Spatial analysis of egg distribution and geographic changes in the spawning habitat of the Brazilian sardine Sardinella brasiliensis.

This paper establishes the spawning habitat of the Brazilian sardine Sardinella brasiliensis and investigates the spatial variability of egg density and its relation with oceanographic conditions in the shelf of the south-east Brazil Bight (SBB). The spawning habitats of S. brasiliensis have been defined in terms of spatial models of egg density, temperature-salinity plots, quotient (Q) analysis and remote sensing data. Quotient curves (Q(C)) were constructed using the geographic distribution of egg density, temperature and salinity from samples collected during nine survey cruises between 1976 and 1993. The interannual sea surface temperature (SST) variability was determined using principal component analysis on the SST anomalies (SSTA) estimated from remote sensing data over the period between 1985 and 2007. The spatial pattern of egg occurrences in the SBB indicated that the largest concentration occurred between Paranaguá and São Sebastião. Spawning habitat expanded and contracted during the years, fluctuating around Paranaguá. In January 1978 and January 1993, eggs were found nearly everywhere along the inner shelf of the SBB, while in January 1988 and 1991 spawning had contracted to their southernmost position. The SSTA maps for the spawning periods showed that in the case of habitat expansion (1993 only) anomalies over the SBB were zero or slightly negative, whereas for the contraction period anomalies were all positive. Sardinella brasiliensis is capable of exploring suitable spawning sites provided by the entrainment of the colder and less-saline South Atlantic Central Water onto the shelf by means of both coastal wind-driven (to the north-east of the SBB) and meander-induced (to the south-west of the SBB) upwelling.

Distribution and abundance of carangid larvae in the southeastern Brazilian Bight during 1975-1981

Distribution and abundance of the carangid larvae collected during ten survey cruises in the southeastern Brazilian Bight were analyzed. Trachurus lathami was the most abundant species in the surveyed area with 58.54 % of total carangids taken, followed by Chloroscombrus chrysurus with 15.22 % and Decapteruspunctatus with 12.17 %. Larvae of T lathami and D. punctatus were found all over the continental shelf while the distribution of C. chrysurus larvae was limited to the coastal region. Most of the species occurred all year-around but remarkably during spring and summer. This intensive spawning period of most carangid species seems to be related to the seasonal variation of the hydrographie structure of the southeastern coast of Brazil.

Ichthyoplankton distribution and abundance in the northern Todos os Santos and Camamu Bays, Bahia State - Brazil

The occurrence, distribution and abundance of ichthyoplankton in Todos os Santos and Camamu Bays were analyzed based on four samplings (winter 2003, summer 2003, winter 2004 and summer 2005). Samples were obtained by surface horizontal hauls, using a 200-µm mesh conical-cylinder plankton net. The distribution and abundance of eggs indicate a remarkable seasonal and annual variation of spawning activity in the region, especially when the two summer campaigns are compared. In summer 2003 the highest quantitative values were recorded, especially for Camamu, where the maximum reached 106.56 eggs.m-3, with an overall average of 43.46 eggs.m-3 for the two areas. In summer 2005 values were relatively low, the overall average being 3.49 eggs.m-3. The larval taxonomic composition is characterized by the predominance of gobiids, with small variation from summer to winter. Considering all the campaigns and samplings undertaken in both areas, larvae of 11 families were identified: Engraulidae, Clupeidae, Mugilidae, Atherinopsidae, Hemiramphidae, Syngnathidae, Blenniidae, Carangidae, Gobiidae, Achiridae and Tetraodontidae.

Larval fish of the Campos Basin, southeastern Brazil

Studies on the vertical distribution of larval fish in water masses along the Brazilian coast are very rare. The present study aimed to identify larval fish occurring in the surface (1 m) layer and at depth in four water masses of the Campos Basin, southeastern Brazil: South Atlantic Central Water (SACW) (250 m), Antarctic Intermediate Water (AAIW) (800 m), Upper Circumpolar Deep Water (UCDW) (1,200 m) and North Atlantic Deep Water (NADW) (2,300 m). Material used in this study was obtained in 2009 through nocturnal horizontal stratified hauls using a Multinet (500 μm mesh size) during both rainy (February to April) and dry periods (August to September). A total of 10,978 fish larvae comprising 169 taxa were identified during the rainy (n = 6,015) and dry (n = 4,963) periods. The number of taxa decreased as the sampling depth increased. Larvae of Clupeidae, Engraulidae and Scombridae dominated in samples collected in the surface layer, while Sternoptychidae and Myctophidae were the most representative families in SACW. The other three water masses were dominated by Gonostomatidae larvae.

Estádios de desenvolvimento dos órgãos reprodutivos dos machos de Panulirus echinatus Smith (Decapoda: Palinuridae)

Esta pesquisa caracteriza os estadios de desenvolvimento dos testiculos e canais deferentes da lagosta Panulirus echinatus Smith, 1869 a partir da relacao entre seus aspectos macroscopicos, microscopicos e a relacao gonadossomatica (RGS). Atraves de amostragem mensal (novembro de 1999 a outubro de 2000) foram capturados 1716 machos, empregando-se redes de espera de fundo. Retirou-se a regiao dorsal da carapaca para avaliacao dos orgaos reprodutivos. Os testiculos e canais deferentes foram dissecados, pesados, fixados em solucao de Bouin e submetidos aos procedimentos histologicos. A analise microscopica dos orgaos reprodutivos foi avaliada pela presenca ou ausencia de espermatozoides nos testiculos e canais deferentes. Esta, quando associada a macroscopia (mudanca de cor, tamanho, diâmetro e desenvolvimento de espermatoforo) e a relacao gonadossomatica (RGS), possibilitou a caracterizacao de tres estadios de desenvolvimento: imaturo, intermediario e maturo. Ficou evidenciada que a maturidade dos testiculos precedeu a maturidade dos canais deferentes. Para avaliar se a RGS e um bom indicador quantitativo dos estadios de maturidade, um teste t (a = 0,05) foi usado e constatou diferenca significativa nas medias da RGS. A RGS pode ser utilizada como indicadora dos estadios de maturidade para P. echinatus.

Comparison of the diel and spatial distribution patterns of ichthyoplankton and ichthyoneuston in the Southeastern Brazilian Bight

Fish larvae were collected by neuston and bongo nets, in the Southeastern Brazil, during four oceanographie cruises (January 1980; January 1981; October 1981; and March 1982). The results are compared and analyzed in order to study the patterns of diel vertical distributions of fish larvae and to detect sampling problems. Larvae collected with neuston net were quite different in types and size composition, when compared with those collected with bongo net in oblique tows. Clear tendency of stratification in size composition at the uppermost layer can be observed on juveniles ( > 19 mm) of Sardinella brasiliensis which also showed day time avoidance. Most of the neustonic taxa were also caught in the deeper layers, although some groups, e.g. Mugilidae, Mullidae, and Gerreidae, were more abundant at the surface. Density of ichthyoneuston is much higher than those observed in the Northwest Atlantic and number of fish larvae collected during the day by neuston net exceeded that of night samples.

Growth and mortality of larval Myctophum affine (Myctophidae, Teleostei)

The growth and mortality rates of Myctophum affine larvae were analysed based on samples collected during the austral summer and winter of 2002 from south-eastern Brazilian waters. The larvae ranged in size from 2·75 to 14·00 mm standard length (L(S)). Daily increment counts from 82 sagittal otoliths showed that the age of M. affine ranged from 2 to 28 days. Three models were applied to estimate the growth rate: linear regression, exponential model and Laird-Gompertz model. The exponential model best fitted the data, and L(0) values from exponential and Laird-Gompertz models were close to the smallest larva reported in the literature (c. 2·5 mm L(S)). The average growth rate (0·33 mm day(-1)) was intermediate among lanternfishes. The mortality rate (12%) during the larval period was below average compared with other marine fish species but similar to some epipelagic fishes that occur in the area.

Biometric relationships of the spotted lobster, Panulirus echinatus , from Tamandaré coastal reefs, Pernambuco State, Brazil

Biometric relationships were recorded for 2431 male and female Panulirus echinatus sampled at Tamandare coastal reefs, Pernambuco, Brazil. The following body measurements were taken: carapace length and width, abdomen length and width, total length, third and fifth pereiopod length, cephalothorax-abdomen and total weight. Twelve relationships were studied to compare the biometric characteristics of males and females. Eleven of them showed difference between the sexes. Comparing sexes with the same carapace length, males have a heavier cephalothorax and longer third and fifth pereiopods than females, whereas females are longer, wider, and have a heavier abdomen than males. For genders with the same total length, males are heavier and have a longer carapace than females, while females have a larger abdomen. For genders with the same abdomen length, males have a heavier abdomen than females. The relationships TWg/TL and A Wg/AL showed positive allometric growth for the males. All other relationships involving weight, presented negative allometric growth for both sexes.

Desenvolvimento dos ovários da lagosta Panulirus echinatus (Crustacea: Palinuridae) baseados nas análises macroscópica, microscópica e relação gonadossomática (RGS)

The developmental stages of the ovaries of the lobster Panulirus echinatus Smith, 1869 were characterized using macroscopic and microscopic features and the gonadosomatic relation (GSR). Based on monthly samples (November, 1999 to October, 2000), a total of 711 females were captured using gillnets. The dorsal region of the carapace was removed to evaluate the ovaries, which were dissected, weighted, preserved in Bouins solution, and submitted to histological procedures. The microscopic analysis of the ovaries was assessed by the presence of germinative cells in different developmental phases. When this analysis was combined with macroscopical observations (changes in color and volume of the gonads in the cephalothorax) and GSR, five developmental stages could be identified: immature (I), intermediate (II); pre-maturation (III); mature (IV) and post-spawning stage (V). Statistical analyses confirmed that GSR can be used as an indicator of developmental stage.

Condition of the Brazilian sardine, Sardinella brasiliensis (Steindachner, 1879) larvae in the São Sebastião inner and middle continental shelf (São Paulo, Brazil)

Institut fur Meereskunde an der Universitat Kiel (Dusternbrooker Weg, 20, Kiel, Germany D-24105) Brazilian sardine is the most important target of purse seine fisheries along Southeastern Brazilian Bight. Fluctuations in the catch during the past 50 years have been noticeable (Matsuura, 1998; Cergole