Ubatuba Region Research Articles

228Ra and 226Ra in coastal seawater samples from the Ubatuba region: Brazilian southeastern coastal region

The present work reports 228Ra and 226Ra results obtained during the 4th Submarine Groundwater Discharge (SGD) intercomparison experiment realized in Ubatuba, November 2003, aiming to test the methodologies on a fractured crystalline rocks system. Although with distinct objectives, it was decided to participate in this experiment in order to verify if radium isotopes could be used to determine water mixing rates in this region and to test the laboratory capability to perform, later on, a marine dispersion model validation at Angra dos Reis reactor site, located nearby. The results show that the SGD model constrains seems to be valid, at least for a distance of 20 km offshore, that corresponds to the distance between the reactor site and Ilha Grande, a 193-km2 island existing at this site and probably an additional SGD source. Salinity, barium and silica results are also reported and their relation to 228Ra concentrations is discussed.

Sea Turtle Conservation in Ubatuba, Southeastern Brazil, a Feeding Area with Incidental Capture in Coastal Fisheries

ABSTRACT Since 1991, Projeto TAMAR-IBAMA, the Brazilian sea turtle conservation program, has maintained a station in Ubatuba, State of Sao Paulo, southeastern Brazil, a feeding area for sea turtles where incidental capture in coastal fisheries occurs. We present an overview of the local fishing methods, explain the conservation approach and field methods employed by TAMAR in the region, present biological data collected between 1991 and 1998, and provide an assessment of the conservation status of sea turtles in the Ubatuba region. During the study period, 2,515 captures of sea turtles were recorded, comprising four species: green turtles (Chelonia mydas, 98.4% of total captures, generally juveniles), loggerheads (Caretta caretta), hawksbills (Eretmochelys imbricata), and leatherbacks (Dermochelys coriacea). Most of the data come from turtles incidentally captured in fishing gear, mainly by artisanal methods. The available data suggest that Ubatuba is a developmental habitat for juvenile green turtles.

Morphometry of the crab Hexapanopeus schmitti (Decapoda: Xanthoidea) on the northern coast of the state of São Paulo, Brazil

A morphometric study of the xanthoid crab Hexapanopeus schmitti was carried out, using the allometric method. Samples were taken monthly for two years (1998-1999) in the Ubatuba region, northern coast of São Paulo, Brazil. Sex and size were assessed for each specimen, and all crabs were measured to obtain their carapace width (CW) and length (CL), abdomen width (AW) of females, major cheliped propodus length and height (PL and PH), and gonopod length (GL) of males. A total of 301 crabs were analyzed, 209 males and 92 females. The CWs of the crabs ranged from 2.5 to 9.8 mm for males and from 2.8 to 9.4 mm for females. The relative growth equation (y=ax^b) based on the relationship between GL and CW suggested that males reach their morphological sexual maturity near 6.1 mm CW. In females, the estimated size at 50 % maturity was 4.8 mm CW, based on the relationship of AW vs. CW. Males reach larger sizes than females, which probably favors their ability to guard the females during courtship. In approximately 83 % of the crabs (n= 371), disregarding sex, the right cheliped was larger.

Biological parameters and population structure of psammobatis extenta in ubatuba region, north coast of the state of são paulo, brazil

specimens of the zipper sand skate psammobatis extenta were collected in the region of ubatuba off the northern coast of the state of são paulo, brazil, monthly for one year (january–december 2000), at 25- to 40-m isobaths. a total of 123 individuals were caught. the total length (tl) of females averaged 224.6 mm, and of males 217 mm. the overall sex ratio was 1:1. analysis of the length–weight relationship indicated the existence of positive allometry in females, and isometry in males. the length at onset of sexual maturity was determined for both sexes; females reached sexual maturity at smaller sizes than males (tl50=230.7 and tl50=237.7 mm respectively). females showed functional parity of both ovaries and uteri. females that were pregnant or were carrying vitellogenic oocytes were observed during nine of the 12 months of the survey, indicating a continuous reproductive cycle. psammobatis extenta was most abundant from january to april, and again from june to october. most individuals were collected at the 40-m isobath. both adults and neonates were collected in the study area. however, adolescent skates were scarce, which either indicates differential occupation of the area, or suggests that the shallow waters of the continental shelf are used as breeding grounds.

Annual, seasonal and spatial variation of abundance of the shrimp Artemesia longinaris (Decapoda: Penaeoidea) in south-eastern Brazil

The influence of several environmental factors on the abundance and spatial–temporal distribution of the shrimp Artemesia longinaris were investigated from January 1998 to December 1999 in the Ubatuba region of São Paulo State, Brazil. Collections were performed monthly in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Six sampling transects were established in each bay, four were parallel to the shore line, and two were next to the rocky shores. A commercial shrimp fishing boat equipped with two ‘double-rig’ nets was used. A total of 11,503 individuals was collected, including 1633 from UBM, 6344 from UBA and 3526 from MV. The majority of the captured specimens came from the deeper areas (15 to 20 m) with high salinity (34 to 36 ppt). The highest abundance of A. longinaris in Ubatuba bay was recorded in areas where fine and very fine sand comprised more than 70% of the sediment. Moreover, the abundance of A. longinaris followed a seasonal trend, being higher during the summer, when intrusions of cold South Atlantic Coastal Waters (SACW) are frequent. Thus, type of sediment, temperature and salinity are determinant factors in the distribution of A. longinaris in the studied region.

Ecological distribution of the shrimp Pleoticus muelleri (Bate, 1888) (Decapoda: Penaeoidea) in southeastern Brazil

The abundance and ecological distribution of the shrimp Pleoticus muelleri as a function of certain environmental factors were investigated from January 1998 through December 1999 in the region of Ubatuba, Sao Paulo, Brazil. The collections were made monthly in the bays of Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Each bay was divided into six sampling transects, four transects parallel to the shoreline and two near the rocky shores on the opposite side. We employed a commercial shrimp boat equipped with two double-rig nets. A total of 6252 shrimp were collected, including 3321 from MV, 1467 from UBM, and 1464 from UBA. Most of the shrimp were caught in the deeper, higher-salinity areas. The high abundance of P. muelleri observed in the southern part of the region studied was related to a sediments with a higher percentage of silt and clay. The numbers of P. muelleri were positively correlated with periods of cooler temperatures. Thus, temperature and the type of sediment were determinant factors in the distribution of P. muelleri in this region.

Biodiversity of brachyuran crabs (Crustacea: Decapoda) from non-consolidated sublittoral bottom on the northern coast of São Paulo State, Brazil

The brachyuran community of the coast of Sao Paulo State is represented by about 188 species of crabs inhabiting different kinds of coastal marine environments. The biodiversity of brachyurans found on non-consolidated sublittoral bottom was investigated. The Ubatuba region (Ubatumirim, Ubatuba and Mar Virado bays, Couves and Mar Virado Islands, offshore region) was sampled for 3 years (1998-2000), at depths of 2-40 m. All sampling was performed using a fishing boat equipped with two double-rig nets. We collected 79 brachyuran species representing 9 superfamilies (4 Dromioidea, 1 Homoloidea, 2 Calappoidea, 5 Leucosioidea, 20 Majoidea, 7 Parthenopoidea, 17 Portunoidea, 18 Xanthoidea, and 5 Pinnotheroidea) and 41 genera. Ubatuba bay showed the greatest species richness with 50 species, followed by Ubatumirim with 45 and Mar Virado with 29. The number of species collected represents about 57% of the known species of crabs already reported for the shore of Sao Paulo State. It is worth noticing that this percentage is restricted only to non-consolidated sublittoral bottom. This fact indicates a great biodiversity of the habitat in this studied region, probably one to the diversity of habitat types present in the bays.

Reproductive Biology of the Shrimp Rimapenaeus Constrictus (Decapoda, Penaeidae) in the Ubatuba Region of Brazil

Abstract Sexual maturity, temporal reproductive pattern, and recruitment of juveniles were examined for the shrimp Rimapenaeus constrictus at three different bays in the Ubatuba region (Mar Virado, Ubatuba, and Ubatumirim), State of Sao Paulo (23°S 45°W). Monthly samples were taken from January 1998 to December 1999. The presence or absence of mating plugs (associated with mating and insemination) and ovarian maturity were used to examine breeding in adult females. The whole sample comprised 3863 females and 1468 males. Estimates of size (carapace length) at the onset of sexual maturity were 7.0 mm and 7.8 mm for males and females, respectively. Higher percentage of females bearing ripe gonads was observed during spring and summer over the course of the study, contrasting to the low proportion in fall 1998 and winter 1999. Juvenile shrimps were sampled year-round. These results suggest a continuous reproductive pattern for R. constrictus. Mating, spawning, and juvenile recruitment took place mostly in sha...

Fecundity of the arrow crab Stenorhynchus seticornis in the southern Brazilian coast

The arrow crab Stenorhynchus seticornis (Brachyura, Majidae), is a common inhabitant of the rocky subtidal along the Brazilian coast. Fecundity and the influence of environmental variables on egg production are investigated in this study. Information on egg size and egg loss through incubation are also provided. Monthly samples were conducted using SCUBA diving, from January to December 1998 in the Ubatuba region (23°25′25[double prime or second]S–44°52′03[double prime or second]W), south-eastern Brazilian coast. Early broods were used for the estimation of size-specific relationships of fecundity. Egg loss was assessed by comparing average egg numbers of early and late broods. The fecundity was estimated in 621.1±339.6 eggs, with an average diameter of 0.48±0.1 and 0.57±0.1 mm for early and late eggs, respectively. The number of eggs produced was apparently constant year-round. No significant differences were recorded among monthly fecundity values. The variation of abiotic factors did not show any relationship with temporal variability of fecundity, suggesting that the environmental effect in egg production is slight at best.

Parasites and Symbionts of Crabs from Ubatuba Bay, São Paulo State, Brazil

During July 1999, 172 crabs from Ubatuba Bay, Sao Paulo, Brazil, were examined from 4 families as follows: Portunidae, Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Charybdis hellerii, Portunus spinimanus, and Portunus spinicarpus; Calappidae, Hepatus pudibundus; Majidae, Libinia ferreirae; Leucosiidae, Persephona mediterranea and Persephona lichtensteinii. One cephaline gregarine symbiont was found in the hindgut of a specimen of Cal. ornatus, and no positively identified, internal and multicelled symbionts were detected. Twenty-one specimens (14.3%) from 7 of the 10 species (all except H. pudibundus, P. mediterranea, and P. lichtensteinii) carried the nemertean worm, Carcinonemertes carcinophila ct. imminuta in either their egg masses or gills. This is the first report of this epibiont from the Ubatuba region. Two specimens of an undescribed polychaete worm were found in the gill of a specimen of L. ferreirae. A stalked barnacle, Octolasmis lowei, was found on the gills of 11 crabs (7.5%). Only 3 crab species (36.6% of Cal. danae, 9.0% of Cal. ornatus, and 7.7% of Po. spinimanus) carried the typical barnacle, Chelonibia patula, on their dorsal carapaces. The percentage of individuals of Cal. danae and Cal. ornatus hosting barnacles (prevalence) as well as the number of barnacles on individual crabs was positively correlated with crab size.

Chave ilustrada para identificação dos camarões dendrobranchiata do litoral norte do estado de São Paulo, Brasil

O presente estudo teve como objetivo a elaboração de uma chave de identificação ilustrada para diferenciar as espécies de camarões marinhos Dendrobranchiata, com ocorrência no litoral do Estado de São Paulo até a profundidade de 40m. As 13 espécies apresentadas neste trabalho foram obtidas mediante coletas mensais durante os anos de 1995 a 2000 na região de Ubatuba, SP . Nesta chave estão incluídas as espécies de interesse econômico, como os peneídeos Xiphopenaeus kroyeri, Farfantepenaeus brasiliensis, F. paulensis, Litopenaeus schmitti, Artemesia longinaris e o solenocerídeo Pleoticus muelleri. Além destas espécies, também foram adicionados os camarões que não são alvos das frotas pesqueiras, entre eles, Rimapenaeus constrictus, Acetes americanus, Peisos petrunkevitchi e os sicionídeos Sicyonia dorsalis, S. typica, S. laevigata e S. parri. A chave proposta servirá como uma ferramenta no auxílio da identificação dos camarões Dendrobranchiata, quer seja por pesquisadores ligados à área científica, como também por pessoas relacionadas aos órgãos responsáveis pelo controle da pesca, principalmente, na época do defeso.

ESR dating of a subfossil shell from Couve Island, Ubatuba, Brazil

The occurrence of subfossil material in bottom sediments of Couve Island, Ubatuba region, São Paulo State, is confirmed. The analyzed material consists of a bivalve shell that was dated by the electron spin resonance technique. By the additive irradiation method an archaeological absorbed dose of (25±5) Gy was obtained and calibration with other dating works in the same area allows the inference of an age of (25±5)×10 2 years. The importance of this finding and its paleoecological implications could contribute to elucidating the nature of short-term environmental changes in the Brazilian coastline during the Holocene, as well as becoming an important tool to the understanding of the distribution and biological aspects of the bivalve fauna.

On a record of Dardanus venosus (H. Milne Edwards) (Crustacea, Anomura) from the São Paulo State, Brazil

The present work is the first report of Dardanus venosus (H. Milne Edwards, 1848) in Sao Paulo State and extends the range of this species in the western Atlantic farther to the south in the Brazilian region. A total of twenty two males (mean shield length: 7.56 ± 1.62 mm, 4.7 to 10.9 mm), and fifteen females (7.25 ± 2.53 mm, 4.3 to 14.5 mm) were collected in 1987, 1998, 1999 and 2000 by scuba diving from three areas of Anchieta Island (23o33'S, 45o05'W) in the Ubatuba region, and south of Sao Sebastiao Island (23o57.8'S, 45o16'W), northern coast of Sao Paulo State. No ovigerous females were captured during the study period. Shells of eleven gastropod species were occupied by D. venosus: Astraea latispina (Philippi, 1844), A. olfersii (Philippi, 1846), A. phoebia Roding 1798, Calliostoma bullisi Clench & Turner 1960, Chicoreus tenuivaricosus (Dautzenberg, 1927), Cymatium parthenopeum (von Salis, 1793), Olivancillaria urceus (Roding, 1798), Phalium granulation (Born, 1778), Stramonita haemastoma (Linnaeus, 1767), Strombus pugilis Linnaeus, 1758 and Zidona dufresnei (Donovan, 1823).

Relative growth and sexual dimorphism of the South Atlantic hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) from Ubatuba, Brazil

Some morphometric relationships and biometric aspects were studied in the hermit crab Loxopagurus loxochelis (Moreira, 1901) with the purpose of describing its relative growth and finding the size where sexual maturity is reached. Specimens were collected monthly from September 1995 to August 1997 in the Ubatuba region using double-rig trawl nets. A total of 1084 specimens (625 males and 459 females) was analysed. In this species, sexual dimorphism is particularly evident in chela dimensions. Differences between males and females were found in the left propodus length versus cephalothoracic shield length (CSL) and wet weight (WW) versus CSL relationships. Males showed a high positive allometry in chela growth, while females were close to isometry/negative allometry. The size at which a clear differentiation occurred in the growth of the propodus length and in the increase in weight of males and females was between 4.5 and 6.0mm CSL, suggesting that size at which sexual maturity is reached.

PATTERNS OF SHELL UTILIZATION IN PETROCHIRUS DIOGENES (DECAPODA, ANOMURA, DIOGENIDAE) IN THE UBATUBA REGION, SÃO PAULO, BRAZIL

The objective of this study is to investigate the patterns of shell utilization in Petrochirus diogenes in the Ubatuba region, SP, Brazil. Hermit crabs were obtained from 1993 to 1996 with the aid of a shrimp fishery boat equipped with two double-rigged trawling nets. Shells were identified and weighed, and their maximum aperture width was measured. Hermit crabs were weighed, and their shield length was recorded. A total of 634 P. diogenes specimens, occupying shells of 12 gastropod species, was obtained. The shells of Tonna galea, Zidona dufresnei and Strombus pugilis were the most frequently occupied, the first marked by its larger aperture width and lower average weight. Small hermit crabs inhabited a wide variety of gastropod shells due to their higher availability. However, the utilization of T. galea shells became predominant as the crabs attained larger sizes. Differences in weight and aperture width are known to encourage certain shell utilization patterns and may affect growth and reproduction of hermit crabs.

Reproductive cycle of hepatus pudibundus (Herbst, 1785) (Crustacea, Decapoda, Calappidae) in Ubatuba, SP, Brazil.

This study aimed to analyze the reproductive cycle of the crab Hepatus pudibundus (Herbst, 1785). The crabs were collected in Ubatuba, SP (23 degrees 26'S and 45 degrees 02'W) monthly from the July, 1992 to June, 1993. Samplings were performed with an "otter trawl". In the laboratory the crabs were numbered, sexed and measured for their maximum carapace width. The gonad developmental stage and the moult stage were also macroscopically registered. In all sampled months ovigerous females and crabs in both sexes with developed gonad were observed. Moult activity in all size classes was verified. Such fact indicates that this species can suffer moult process after their maturity. In despite of temperature being pointed a one of the most important ecological factor in the reproductive biology of aquatic animals, it was verified any relation between water temperature and ovigerous ratio. The oscillations of the environmental factors in the Ubatuba region sea probably were not enough to alter the continuity of the physiological processes related to H. pudibundus reproduction.

Patterns of Shell Utilization in Petrochirus Diogenes (Decapoda, Anomura, Diogenidae) in the Ubatuba Region, São Paulo, Brazil

The objective of this study is to investigate the patterns of shell utilization in Petrochirus diogenes in the Ubatuba region, SP, Brazil. Hermit crabs were obtained from 1993 to 1996 with the aid of a shrimp fishery boat equipped with two double-rigged trawling nets. Shells were identified and weighed, and their maximum aperture width was measured. Hermit crabs were weighed, and their shield length was recorded. A total of 634 P. diogenes specimens, occupying shells of 12 gastropod species, was obtained. The shells of Tonna galea, Zidona dufresnei and Strombus pugilis were the most frequently occupied, the first marked by its larger aperture width and lower average weight. Small hermit crabs inhabited a wide variety of gastropod shells due to their higher availability. However, the utilization of T. galea shells became predominant as the crabs attained larger sizes. Differences in weight and aperture width are known to encourage certain shell utilization patterns and may affect growth and reproduction of hermit crabs.

Relative growth of Petrochirus diogenes (Linnaeus, 1758) (Crustacea, Anomura, Diogenidae) in the Ubatuba region, São Paulo, Brazil

The purpose of this paper is to investigate the relative growth and heterochely in the hermit crab Petrochirus diogenes. Hermit crabs were collected in the Ubatuba region, SP, from 1993 to 1996; using a commercial fishing boat equipped with two double-rig nets. Body mass of each individual was weighed and their cephalothoracic shield and chelar propodus size were measured. Body mass and chelar propodus size were regarded as dependent variables and plotted against length of cephalothoracic shield according to the allometric equation y = a x x(b). A total of 479 individuals were obtained being 307 males and 172 females. Cephalothoracic shield width follows an isometric growth for both sexes. Otherwise, right cheliped dimensions show different relative growth patterns and left cheliped ones present a positive allometry in males and females. Unlike brachyurans, ontogenetic changes in the growth rate of chelar propodus are not clearly discernible, which prevents the accurate detection of allometric variations. In both sexes, the right cheliped is larger than the right one. Cheliped size is a sexual dimorphic feature with males bearing larger chelipeds than females. Heterochely may be particularly adaptive in agonistic interactions and precopulatory behaviour in P diogenes.

Reproductive cycle of the swimming crab Portunus spinimanus Latreille (Crustacea, Decapoda, Brachyura) from Ubatuba, São Paulo, Brazil

This study analyses some reproductive aspects of Portunus spinimanus Latreille, 1819, a crab usually commercialized in Ubatuba region. Monthly otter-trawl collections were taken for two years along the northern coast of Sao Paulo State, Brazil. The reproductive period was studied based on the frequency of ovigerous females in the population along the year; the frequency of physiologically mature swimming crabs and the type of spawn. The condition of development of ovigerous females ovary was associated with the stage of eggs development. This species presents continuous reproduction in Ubatuba region and total spawn, but with successive broods, which suggests a multiple spawn during the reproduction period.

Environmental forcing on phytoplankton biomass and primary productivity of the coastal ecosystem in Ubatuba region, southern Brazil

A time series of chlorophyll a and in situ primary production sampled over a period of 33 days during summer in Ubatuba region, southeastem Brazil, was subjected to multivariate and harmonic analysis. Principal Component Analysis has revealed four factors interpreted as (i) South Atlantic Central Water forcing; (ii) Transient ftontal systems and rain fali forcings; (iii) Wind forcing normal to the coast; (iv) Wind forcing parallel to the coast, as main factors in the variability of the phytoplankton biomass and primary productivity. Splitting of the time series according to four main events which had profound effects on the physicochemical characteristics of the region showed the following variations in the primary productivity integrated over the photic layer (g C m-2 day-1): mixing→stratification period, 0.40 ± 0.11; heavy rainfall, 1.24± 0.28; stratification after rainfall, 0.74± 0.10; stratification→mixing period, 0.90± 0.27; stratification after deep mixing, 0.63 ± 0.28. Harmonic analysis revealed two indistinguishable significant peaks of the phytoplankton biomass - one at a period of 8.25 days and one at a period of 6.6 days, contributing, respectively, about 17 and 32% ofthe total variance. Atmospheric forcing showed a characteristic period,of 200-264 hours while phytoplankton biomass response ranged over the 144-192 hours time scales and primary productivity was best related to the environment 360 hours before. Relative to total nitrogen' and ' biomass primary productivity oscillations were lagged about 96-144 hours. The interruption of steady-state conditions by transient atmospheric ev~nts and wind field intensification are the determining factors driving phytoplankton changes in this coastal environment.