Abstract We present here the first record of Salacia tetracythara as an alien species for the Atlantic Ocean, specifically the coast of the state of Sergipe, northeast Brazil. The species was found attached to an artificial experimental plate installed in the rainy period (July-October 2017), in an estuarine region of the Sergipe River near the Sergipe Harbour. Salacia tetracythara is characterized by a small triangular space below each hydrotheca and two types of microbasic mastigophore nematocysts that differ in shape, size, and location. The species was described from Australia and has been recorded only for tropical to temperate regions of the Indo-Pacific. Salacia tetracythara seems to be a recent introduction into the Atlantic Ocean and, its introduction probably derived from ship transport between the Sergipe Harbour and regions of Oceania and/or Asia. Further investigation should be conducted to determine whether the species is established in the region and how far inside the estuary it has gone.

Apesar do número relativamente elevado de estudos recentes sobre Cnidaria da costa brasileira, encontramos dois casos de parasitismo, ambos em macromedusas, e nenhum em pólipos. Associações endoparasíticas entre larvas de picnogônidas e hidroides são bem conhecidas desde início do século 20. A larva protoninfa desenvolve-se no interior da cavidade gastrovascular dos pólipos, geralmente dos gastrozoóides, que são então chamados “gallzooids”. Esta nota é um registro inédito de parasitismo em pólipos de cnidários da fauna brasileira. A associação parasitária entre o picnogônida Anoplodactylus stictus e uma espécie nova de hidroide do gênero Podocoryna foi detectada casualmente sobre a comunidade incrustante de placas experimentais, instaladas no Iate Clube de Paranaguá, Paranaguá, sul do Brasil, de fevereiro/2007 a fevereiro/2008. O hospedeiro hidrozoário provavelmente é uma espécie exótica, pois não havia sido observado em estudos anteriores da Baía de Paranaguá ou praias ao longo da costa sul do Brasil nos últimos 20 anos. Foram analisadas 88 colônias do hidroide das quais 19 estavam parasitadas, principalmente nos meses de junho a agosto/2007. As protoninfas eram rosa-avermelhadas, a mesma coloração dos “gallzooids” e dos demais pólipos da colônia, indicando que elas ingeriram tecidos do hospedeiro. Até seis protoninfas foram observados no interior dos “gallzooids”. O comprimento da coluna dos “gallzooids” alongava e os tentáculos atrofiavam ou mesmo desapareciam devido ao desenvolvimento das larvas. Algumas observações do endoparasitismo em duas colônias vivas mantidas em aquários, até seu desaparecimento completo (um mês), também são descritas nesta nota.

Despite the relatively high number of recent studies on Cnidaria off the Brazilian coast, we have observed only two records of parasitism on macromedusae and none on polyps. Endoparasitic associations between Pycnogonida larvae and hydroids have been well known since the early 20th century. Protonymph larvae develop inside the gastrovascular cavity of polyps, typically gastrozooids, which are then called gallzooids. This short communication is an unprecedented record of parasitism on the polyps of Brazilian cnidarian fauna. The parasitic association between Pycnogonida Anoplodactylus stictus and a new hydroid species of Podocoryna has been casually detected on the encrusting communities of experimental polyethylene plates installed at the Paranaguá Yacht Club, Paranaguá, south of Brazil from February 2007 to February 2008. This hydrozoan host is most likely an exotic species because it had not been observed in previous studies of Paranaguá Bay or beaches along the southern coast of Brazil in the previous 20 years. Eighty-eight hydroid colonies were analyzed, of which 19 were parasitized mainly from June to August 2007. Protonymphs were pink-red colored, similar to gallzooids and all other polyps of the colony, thus indicating that they had eaten the hosts' tissues. Up to six protonymphs were observed inside the gallzooids. The gallzooid column was elongated, and the tentacles were atrophied or even absent because of the development of the larvae. Some observations of endoparasitism in two live colonies that were maintained in aquaria until their complete disappearance (one month) are also described in this note.

A fauna de hidroides bentônicos do infralitoral raso, de seis locais do município de Bombinhas (Santa Catarina, Brasil), foi pesquisada e analisada com base na morfologia. O cnidoma foi examinado quando necessário para a identificação específica. Foram encontradas 25 espécies, das quais cinco (20%) são registradas pela primeira vez para o estado de Santa Catarina e três (12%) são registradas pela primeira vez para a região sul do Brasil. Houve um acréscimo de 12% e 5,5% nos registros de espécies de hidroides para Santa Catarina e litoral sul brasileiro, respectivamente.

The benthic hydroid fauna from shallow subtidal zone of six localities in the municipality of Bombinhas (state of Santa Catarina, Brazil) was surveyed and its morphology analysed. Cnidome was also examined when it was necessary for species identification. Twenty five morphospecies were found, from which five (20%) were recorded for the first time in Santa Catarina State and three (12%) were recorded for the first time in the south region of Brazil. There was a 12% and 5.5% increase in the records of benthic hydroid species for Santa Catarina and southern Brazilian coast, respectively.

Substratos de diferentes materiais, cores, texturas e orientação podem influenciar seletivamente no recrutamento de invertebrados sésseis e, assim, influenciar a comunidade resultante. Deste modo, o substrato pode funcionar como barreira contra o estabelecimento de espécies não nativas (NIS, na sigla em inglês). No sul do Brasil, o granito é a principal rocha formadora de costões rochosos naturais disponíveis para organismos incrustantes. Nesta investigação, nós testamos se o granito seleciona o recrutamento de espécies e se poderia, assim, impedir a colonização de espécies introduzidas ou criptogênicas já estabelecidas em substratos artificiais na região. Placas não polidas de granito e de polietileno foram submersas a cada mês em um píer de um iate clube na Baía de Paranaguá. Há uma comunidade já estabelecida sobre colunas de concreto e sobre flutuadores de fibra de vidro presentes no iate clube. Depois de um, dois e doze meses, as espécies presentes nas placas de diferentes materiais foram comparadas entre si e também com outros substratos. O granito foi colonizado por todas as sete espécies introduzidas encontradas na região, e por 18 das 26 espécies criptogênicas, sendo então ineficaz como barreira contra a colonização de NIS.

Different substrates of varying composition, color, texture and orientation may selectively influence recruitment of sessile invertebrates and thereby influence the resultant community. Thus substrates may act as a barrier to the establishment of non-indigenous species (NIS). In southern Brazil, granite is the main rock forming natural rocky walls that are available for encrusting organisms. In this study we tested whether granite selectively influences recruitment and impedes colonization by introduced and cryptogenic species that are already established on artificial substrates within the region. Plates of rough cut granite and of polyethylene were made available each month under a pier at a yacht club in Paranaguá Bay. A community is already established on concrete columns and fiber glass floats on the piers. After one, two and twelve months, the faunal composition of the plates was compared between the two treatments and other artificial substrates. Granite was recruited by all the seven introduced species found in the Bay and by 18 of 26 cryptogenic species and therefore is ineffective as a barrier to NIS colonization.

Seasonal variation of large medusae abundance and biomass was studied in the North Bay, Santa Catarina, southern Brazil (27°30'S, 48° 32'W), from February to December 2005. Collecting was conducted seasonally with the help of fishing bottom trawl in 30-minute sections (12 in summer, 18 in each of the remaining seasons) in six stations, totaling 66 samples. Eight species were found: the hydrozoans Aequorea sp., Olindias sambaquiensis Müller, 1861, and Rhacostoma atlantica L. Agassiz, 1850; the cubozoans Chiropsalmus quadrumanus (Müller, 1859) and Tamoya haplonema Müller, 1859, and the scyphozoans Aurelia sp., Chrysaora lactea Eschscholtz, 1829 and Lychnorhiza lucerna Haeckel, 1880. Capture rates were low, up to 38 indiv. ha-1, and only ~47% of the samples were positive for jellyfish, comprising 206 individuals. Medusae abundance and species richness clearly changed from one season to another, but did not vary between the sites. Higher species richness (7 out of 8) and greater abundances were recorded during the fall (~60% and 72% of all medusae individuals and biomass respectively). Specific frequency of capture varied from 1.5 to 29% and C. lactea was the only species found in more than 25% of the samples. The three most common species dominated in different periods of the year: C. lactea during fall (78% of individuals and 60% of biomass), R. atlantica during winter (90% of individuals and 17% of biomass), and O. sambaquiensis in spring (78% of individuals and 40% of biomass). Only two individuals were caught during summer, one C. lactea and one R. atlantica. The results offer a general picture of the distribution of the macromedusae in the North Bay, but a continuous monitoring is desirable for a more detailed knowledge on the jellyfish dynamics in the Brazilian coastal waters.

A dieta das cubomedusas Tamoya haplonema Müller, 1859 (Carybdeidae) e Chiropsalmus quadrumanus (Müller, 1859) (Chirodropidae) foi analisada em espécimes coletados no litoral do Paraná (25º20' - 25º55'S; 48º10' - 48º35'W), sul do Brasil, entre dezembro de 1998 e dezembro de 2004, e é o primeiro estudo a abordar este aspecto da biologia de Cubozoa no Atlântico Sul. A cavidade gastrovascular da maioria (55%) dos 29 exemplares de T. haplonema mostrou-se vazia, e dos demais continha partes corporais de peixes teleósteos, como escamas, vértebras e otólitos. Em 726 exemplares de C. quadrumanus os itens alimentares mais importantes foram o camarão sergestídeo Peisos petrunkevitchi Burkenroad, 1945 e larvas de Brachyura, principalmente megalopas. Pequenos caranguejos, isópodes, peixes, ovos de peixes e nematóides foram menos comuns. Mudanças na dieta evidenciaram-se durante o crescimento de C. quadrumanus. Indivíduos menores alimentaram-se de maior variedade de presas, principalmente de larvas de Brachyura, e também apresentaram freqüência mais alta de estômagos vazios. À medida que cresciam, a ingestão de larvas diminuía de importância enquanto a do camarão P. petrunkevitchi aumentava, até este se tornar o principal item na dieta da espécie.

The diet of cubomedusae Tamoya haplonema Müller, 1859 (Carybdeidae) and Chiropsalmus quadrumanus (Müller, 1859) (Chirodropidae) was examined in specimens collected on the Southern Brazilian coast (25º20' - 25º55'S; 48º10' - 48º35'W), between December 1998 and December 2004. This is the first study to analyze this biological aspect in cubomedusae from the South Atlantic. The gastrovascular cavities of most (55%; n = 29) specimens of T. haplonema were empty while the remainder had teleosteans parts such as scales, vertebrae and otoliths. In C. quadrumanus (n = 726), the most important items were the pelagic sergestid shrimp Peisos petrunkevitchi Burkenroad, 1945 and Brachyura larvae, mainly megalops. Small crabs, isopods, fish, fish eggs and nematodes were less common. A dietary shift was clearly observed during C. quadrumanus growth. Smaller individuals consumed a greater variety of prey, mostly Brachyura larvae, and they also had higher frequencies of empty stomachs. As their size increased, megalopas decreased and P. petrunkevitchi became the most important item in their diet.