Resumen Lytechinus variegatus (Lamarck) es un equinoide común en la costa atlántica de América, desde Carolina del Norte, Estados Unidos, al sur del Brasil y sus poblaciones habitan ambientes sublitorales de aguas someras. Este trabajo examina algunos aspectos de la reproducción en el límite sur de distribución de la especie. Un total de 86 individuos adultos (50.8 a 77.0 mm de diámetro de testa) fueron colectados manualmente de septiembre de 2000 a setiembre de 2001, en fondos blandos del sector eurihalino de la bahía de Paranaguá (48° 19’ W - 25° 35’ S), para caracterización histológica, proporción de sexos y evaluación del índice gonadal (IG). La población exhibió sincronización en los eventos de maduración y liberación de gametos (otoño e invierno, respectivamente), con una proporción de sexos de 1:1 (χ2 = 2.57, df = 7, p < 0.05). El aumento del IG estuvo asociado a periodos de acumulación de recursos nutricionales (estadios de reposo y proliferación) que ocurrieron entre el final del invierno y el verano. Análisis biométricos indican una gran inversión en tamaño y cantidad de gametos entre final de primavera y verano, cuando es posible observar gametos maduros ocupando, en promedio 63.9 % del lumen folicular, y ovocitos alcanzando diámetros de 70 a 75 μm. El tamaño medio de los ovocitos maduros es el mayor entre los equinodermos regulares de la misma latitud. Sin embargo, el tamaño medio del diámetro de los ovocitos de L. variegatus en su límite sur de distribución es menor que los valores registrados para el hemisferio norte. Llegamos a la conclusión de que a través de su distribuición geográfica extensa, los factores ambientales locales modulan el ritmo y la magnitud de la reproducción en poblaciones de este equinodermo.

Abstract Lytechinus variegatus (Lamarck) is a common echinoid found on the Atlantic coast of America from North Carolina to southern Brazil and their populations inhabit sub littoral shallow-water environments. This research examined some aspects of reproduction in the southern limit of distribution of the species. A total of 86 adult individuals of L. variegatus (50.8 to 77.0 mm test diameter) were manually collected from September 2000 to September 2001 along the unconsolidated bottoms at the eurihaline sector of Paranaguá Bay (48° 19’ W - 25° 35’ S) for histological characterization of gametogenesis, sex ratio and gonadal index (GI) evaluation. This population showed a synchronicity in maturation and spawning events (autumn and winter respectively), with a 1:1 sex ratio (χ2 = 2.57, df = 7, p < 0.05). The GI increase was associated with storage of nutritional resources periods (resting stages and proliferation) that occurred between late winter and spring. Biometric analyzes indicated a greater investment in size and/or quantity of gametes between late spring and summer, when it was possible to observe mature sperm occupying on average 63.9 % of the follicular lumen and oocytes reaching values of 70.0 to 75.0 μm. Mature oocyte mean size is the highest diameter of those developed by other regular echinoids in the same latitude. However, the average diameter of mature oocytes of L. variegatus in the southern limit of its distribution was lower than the values recorded for the northern hemisphere. Rev. Biol. Trop. 63 (Suppl. 2): 243-250. Epub 2015 June 01.

Poluição, exploração de recursos, erosão e atividades recreativas são os impactos mais comuns que de alguma forma alteram o equilíbrio natural do ecossistema praial. O objetivo deste trabalho foi comparar a riqueza e a abundância da macrofauna bentônica entre um setor não urbanizado e outro urbanizado de duas praias morfodinamicamente distintas. Os setores de cada praia foram analisados levando em consideração aspectos morfodinâmicos, antrópicos (atividades recreativas) e ecológicos. Morfodinamicamente, uma das praias apresentou sedimentos formados por areia fina, suave inclinação e morfodinamismo com características dissipativas. A outra praia apresentou sedimentos formados por areia média, perfil íngreme e características morfodinâmicas entre intermediárias a refletivas. Em ambas as praias, durante o verão, o setor urbanizado apresentou maior abundância de usuários do que o setor não urbanizado. Na praia com morfodinamismo dissipativo, relações negativas foram observadas entre a abundância de usuários e a dos organismos Bledius bonariensis, Donax hanleyanus, Thoracophelia furcifera, Excirolana armata, Phoxocephalopsis sp. e Tholozodium rhombofrontalis. Já na praia com morfodinamismo intermediário a refletivo, foram registradas baixas abundâncias de Atlantorchestoidea brasiliensis e Excirolana braziliensis no setor urbanizado. Assim, os resultados do presente estudo sugerem a utilização de algumas espécies como indicadores de impactos antrópicos nos ecossistemas praiais.

Pollution, exploitation of resources, erosion and recreational activities produce the most common impacts that somehow alter the natural balance of beach ecosystems. The aim of this study was to compare the richness and abundance of the benthic macrofauna of two sectors, one non-urbanized and the other urbanized, on each of two morphodynamically different beaches. Sectors of each beach were analyzed taking into account morphodynamic, anthropogenic (recreational activities) and ecological aspects. Morphodynamically, one of the beaches presented sediment formed of fine sand with a gentle slope and morphodynamism with dissipative characteristics. The other was of sediment formed of medium sand with a steep profile and of intermediate to reflective morphodynamic characteristics. On both beaches during the summer, the urbanized sector was frequented by a greater number of users than the non-urbanized sector. On the beach with dissipative morphodynamism, negative relationships were observed between user abundance and the species Bledius bonariensis, Donax hanleyanus, Thoracophelia furcifera, Excirolana armata, Phoxocephalopsis sp. and Tholozodium rhombofrontalis. On the beach with intermediate to reflective morphodynamics, low abundances of Atlantorchestoidea brasiliensis and Excirolana braziliensis were recorded in the urbanized sector. Thus the results of this study suggest the use of certain species as indicators of human impacts on beach ecosystems.

No Brasil, uma pesca industrial de arrasto dirigida à vieira Euvola ziczac teve inicio em 1973 e colapsou após 1980, quando foram desembarcadas 8.800 t. Atualmente os desembarques não têm ultrapassado algumas centenas de quilos. Baseado em cruzeiros de prospecção realizados em 1974-1975 e em 1995-1996, este trabalho descreve as alterações nos padrões de distribuição e abundância relativa do recurso e discute a sua situação atual frente ao ordenamento local da pesca demersal de arrasto. Nos anos 70 E.ziczac concentrava-se num grande banco localizado entre o sul de São Paulo e o norte de Santa Catarina e entre 30 e 50 metros de profundidade. Tal padrão foi profundamente modificado nos anos 90 quando somente duas pequenas agregações muito pouco densas foram encontradas. Os efeitos cumulativos da redução da área de ocorrência e das densidades do recurso sugerem que a sua biomassa foi reduzida em 98%. O enfoque do manejo da pesca industrial de arrasto da região tem se mantido sobre seu antigo recurso-alvo (o camarão-rosa, Farfantepenaeus paulensis e F. brasiliensis), e medidas adicionais não têm sido implementadas, mesmo depois da frota ter redirecionado seu esforço para recursos alternativos da plataforma continental e do talude. Desta forma a situação da vieira E. ziczac fornece um exemplo concreto dos danos irreversíveis que o redirecionamento do esforço pesqueiro não controlado pode ocasionar sobre os estoques, e demonstra a necessidade de mudança no enfoque do manejo da pesca demersal brasileira.

In Brazil, an industrial trawling fishery directed to Euvola ziczac started in 1973 and collapsed after 1980, when scallop landings reached 8,800 t. Since 1995 E. ziczac landings have not surpassed a few hundred kilograms. Based on surveys carried out in 1974-1975 and in 1995-1996, this work assesses temporal changes occurred in scallop distribution and relative abundance patterns and analyzes the current stock situation under the present management regimes applied to the local demersal trawling fishery. In the 1970's E. ziczac was concentrated in a main bed extending from southern São Paulo to northern Santa Catarina States and between 30 and 50 m depth. This pattern changed dramatically during the 1990's, when only two very small and low-density concentrations were found in the region. Cumulative effects of reducing areas and density within the remnant concentrations produced a reduction in the stock biomass of 98%. Management of the local double rig trawler fishery has always focused on its first main target, the shrimps Farfantepenaeus paulensis and F. brasiliensis. Additional measures have not been implemented, even after substantial part of the fleet has directed its effort to alternative shelf and slope resources. The collapse of the Brazilian scallop fishery provides a striking example of irreversible damage caused by uncontrolled fishing redirection allocated to other resources, demonstrating the need of changes in the Brazilian demersal fishery management model.

Scallops were collected from beds at 30 to 40 m depth on the south-southern inner continental shelf of Brazil for histological gonadal characterization of the reproductive cycle. This hermaphroditic scallop was an important shellfish resource during 70-80 decade, with maximal annual landings of 8,845 tons, but now is depleted. Results shows that reproduction is continuous, with two major spawning periods, the first during end of summer and throughout autumn, and the second during winter and beginning of spring. A characteristic phenomenon of oocyte atresia, with maximal incidences in September is described. This phenomenon, followed by the mature oocyte resorption and new oocyte proliferation and maturation, was related to the lack of spawning stimulation. A semi-annual thermal cycle on the bottom water due to the South Atlantic Central Water intrusion seems to be the principal reproductive cycle controller. Fluctuations in landings registered since the beginning of the fishery may be partly related to oceanographic variations.

A macroinfauna bentônica de seis praias próximas a Baía de Guaratuba, no Paraná, Brasil, foi estudada no verão e no inverno de 1994. Estações de coleta biológica e sedimentológica foram distribuídas desde a linha de detritos, na parte superior da praia, até uma profundidade de 3 metros, no infralitoral. O poliqueta Scolelepis squamata foi a espécie numericamente dominante em praias compostas por areia fina a muito fina. O equinóide Mellita quinquesperforata ocorreu nas ultimas estações na zona de arrebentação, e apresentou os maiores valores de biomassa. Os crustáceos foram o grupo mais diverso em todos os tipos de praia. Resultados das analises de classificação e ordenação mostraram um padrão de zonação similar ao esquema de Salvat, com pequenas diferenças entre o verão e o inverno. A analise de correspondência canônica indicou a importância do nível da estação de coleta e da composição granulométrica do sedimento na distribuição dos organismos.

Benthic macroinfauna of six beaches near to Guaratuba Bay, Paraná, Brazil were studied in summer and winter of 1994. Sampling stations were distributed along a transect, from upper of the drift line to depths of nearly 3 m behind the first break of the surf zone. Biological and sedimentological samples, slope, wave height and period were recorded. Subtidal samples were collected by scuba diving. The beaches varied from extremely inclined, composed of coarse sediments, to low inclined, composed of fine and very fine sands. The polychaete Scolelepis squamata, was the numerically dominant species in those beaches composed by fine to very fine sand in the subaereal profile. The echinoderm Mellita quinquiesperforata occurred in the last stations of the surf zone and presented the biggest values of biomass. Crustaceans were the most diverse group across all beach type. Results of classification and ordination analyses showed that zonation pattern fitted better to Salvat’s scheme, with minor differences between summer and winter data. CCA’s analysis indicated the importance of sampling level and granulometric composition in the distribution of organism.

Material collected with a 2-meter wide beam trawl during eight surveys conducted from December 1995 to February 1997 was used for a first preliminary description of the reproduction and population dynamics of the edible venerid bivalve Chione pubera (Bory Saint-Vicent, 1827). Greatest catches were found between 30 to 35 meters depth, on fine sandy bottoms with a mud content lower than 10%. Dry weight meat condition index showed highest values during autumn and lowest values from winter to summer months. Histological analysis of gonadal tissue showed a continuous reproduction, with peaks of maturation on autumn and spring, Spawning was related with the increase of water temperature, that occurs twice a year in the region as a consequence of a particular hydrological characteristic of the inner continental shelf. Size frequency distribution showed a unique principal mode with slow if any displacement through time, indicating a long lived species.

A vieira hermafrodita simultânea Euvola ziczac (anteriormente Pecten ziczac), foi intensamente explotada no Brasil entre os anos de 1972 e 1980. O máximo de produção foi atingido em 1980, com 8800 toneladas desembarcadas, após o qual ocorreu o total colapso do recurso. Com o objetivo de reconhecer uma possível perda de variabilidade genética do estoque associada à sobrepesca e à autofecundação, analisou-se por técnicas eletroforéticas o polimorfismo da fosfoglicomutase (PGM) e da glicose fosfato isomerase (GPI) do músculo adutor de vieiras do banco de São Francisco (26° 20,583’S; 48° 16,507’W) e Bom Abrigo (25° 28,735’S; 47° 37,621’W), nos extremos sul e norte da área de pesca, respectivamente. Os animais de São Francisco mostraram uma forte deficiência de heterozygocidade para a GPI e a PGM. A PGM mostrou também alelos exclusivos deste banco. Estes resultados, junto com outras informações da espécie, levantam às seguintes hipóteses: a) o estoque é uma metapopulação com pelo menos duas populações; b) algum isolamento reprodutivo pode ocorrer influenciado pelas condições de tranporte larval e pelas densidades extremamente baixas dos adultos; c) atualmente o estoque parece manter-se principalmente por autofecundação; d) o banco de São Francisco pode constituir uma área fonte, contribuindo com larvas e recrutas para o banco de Bom Abrigo e outras áreas; e) ambos bancos estariam sofrendo uma homogenização genética, mais evidente em São Francisco. Estas hipóteses necessitam ser investigadas com o objetivo de prover orientação a futuros programas de recuperação e manejo do recurso.

Euvola ziczac (formerly Pecten ziczac), a simultaneous hermaphroditic scallop was heavily fished in Brazil between 1972 and 1980. The production peaked in 1980 with 8,800 tons and was followed by the total collapse of the resource. In order to investigate the possible loss of genetic variability of the stock associated to overfishing and self-fertilization, the polymorphism of phosphoglucomutase (PGM) and glucose phosphate isomerase (GPI) was analyzed by electrophoresis of the adductor muscle of scallops from São Francisco (26° 20.583’S; 48° 16.507’W) and Bom Abrigo (25° 28.735’S; 47° 37.621’W) beds; the southern and northern extremes of the scallop fishing ground, respectively. Animals from São Francisco showed a strong deficiency of heterozygosity for GPI and PGM. In addition, PGM showed *exclusive alleles for each bed. Such results coupled with other information about the species suggested the following hypothesis: a) the stock was a metapopulation with at least two populations; b) some reproductive isolation might be occurring which might be influenced by conditions of larval transport and by the extremely low densities of scallops; c) presently, the stock seemed to be mostly maintained through self-fertilization; d) São Francisco could constitute a source-area, contributing with larvae and recruits to Bom Abrigo and other areas; e) both beds were suffering a genetic homogenization more evident in São Francisco. Such hypothesis needed to be investigated in order to furnish guidelines for future programs of recovery and management of the resource.