ABSTRACT
The Amazon Reef System (ARS) is one of the most important shallow and mesophotic reef ecosystems in the South Atlantic Ocean. The ARS consists mainly of extensive beds of calcareous algae interspersed by assemblages of octocorals and sponges. The enormous freshwater discharge from the Amazon River forms a plume along the extensive Amazon continental shelf, for which the hydroid community is still largely unknown. The aim of this study is to document the diversity and distribution of hydroids from the ARS, as well as to infer the influence of the plume on species composition in the different zones. Samples were collected at ninety-six stations between 15 and 240 m deep on the Amazon shelf. A total of 37 species were recorded in the studied area. Hydroid assemblages are richer in zones under lower river plume influence, and species composition differs significantly between zones with and without plume influence (PERMANOVA, p = 0.0025). The dissolved oxygen and nitrate ranges were the environmental variables significantly correlated with the hydroid distribution. This study is the first surveying the hydroid species composition and richness in the ARS, highlighting the presence of a typical reef biota and that further faunal studies in underexplored areas of the Atlantic should reveal the distribution of many poorly known hydroids species.
Subject(s)
Biodiversity , Coral Reefs , Environmental Monitoring , Rivers , Brazil , Animals , Atlantic Ocean , EcosystemABSTRACT
The genus Callicarpa Fewkes, 1881 presently comprises two species of Leptothecate hydroids. Herein we redescribe one of these, C. chazaliei Versluys, 1899, originally described from Florida and known elsewhere only from Venezuela. With the only morphological account of this species being that of the original description, a detailed redescription and illustrations of it are provided. Specimens were collected in the Potiguar Basin off the coast of Rio Grande do Norte, Brazil, at a depth of 65 m, during a project focusing on the characterization and monitoring of an oil extraction basin.
Subject(s)
Callicarpa , Hydrozoa , Animals , Atlantic OceanABSTRACT
The genus Zygophylax is a genus of leptothecate hydroids considerably rich in the number of species in the deep sea. In this study we review five species, Z. africana, Z. crozetensis, Z. infundibulum, Z. millardae and Z. geminocarpa, from southern Africa based on available material from several collections, describing and illustrating materials from type series or additional material. Additionally, we describe Zygophylax naomiae sp. nov. collected in South Africa at a depth of 287 m, distinguished from its congeners by the strong pattern of annulations of the pedicels of the hydrotheca and the nematotheca.
Subject(s)
Hydrozoa , Animals , South AfricaABSTRACT
The genus Zygophylax Quelch, 1885 includes ca. 50 valid species of leptothecate hydroids that occur mainly in deep waters. Herein we describe Zygophylax kakaiba, sp. nov., collected in the Philippines at a depth of 580 m during the Siboga Expedition. Compared to its congeners, this species is distinguished by the abrupt curvature of the distal third of its hydrothecae towards the adcauline side.
Subject(s)
Hydrozoa/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Hydrozoa/anatomy & histology , Hydrozoa/growth & development , Islands , Organ Size , Pacific Ocean , PhilippinesABSTRACT
O Parque Estadual Marinho de Areia Vermelha (Cabedelo, Paraíba) foi criado pelo Governo do Estado da Paraíba com a finalidade de conservar a biodiversidade local e de regulamentar as atividades turísticas na área. Mais de uma década depois de sua criação, este estudo configura-se no primeiro inventário da macrofauna bêntica desta, que, até então, é a única unidade de conservação completamente marinha do litoral paraibano. Os espécimes estudados provêm de coletas realizadas entre fevereiro e abril de 2008. Durante os trabalhos de campo, os animais foram amostrados através de buscas intensivas nos diversos microhabitats do recife. Foram identificadas 102 espécies distribuídas entre os táxons Cnidaria (13 spp.), Mollusca (57 spp.), Crustacea (15 spp.), Echinodermata (15 spp.) e Ascidiacea (2 spp.). Do total de espécies registradas, 14 são novas ocorrências para o litoral do Estado da Paraíba, são elas: Pennaria disticha, Encope emarginata, Aplysia dactylomela, Arene brasiliana, Hipponix leptus, Olivella nivea, Mancinella deltoidea, Notocochlis isabelleana, Pilsbryspira albocincta, Pilsbryspira zebroides, Cymatium cynocephalum, Mactrellona alata, Mactrotoma fragilis e Mulinia cleryana. Três espécies ameaçadas de extinção de acordo com a legislação brasileira foram registradas: Millepora alcicornis (hidrocoral), Echinaster (Othilia) echinophorus e E. (O.) brasiliensis (estrelas-do-mar). Além disso, uma espécie de crustáceo que habita o Parque é considerada ameaçada de sobreexplotação, a lagosta Panulirus laevicauda. Entre os moluscos, destacam-se as espécies Voluta ebraea e Turbinella laevigata, endêmicas do nordeste brasileiro, que também ocorrem nos limites do Parque e que são particularmente vulneráveis devido à sua relevância no comércio ornamental marinho. Apesar de se tratar de um estudo piloto, a macrofauna bêntica registrada no Parque de Areia Vermelha revelou a presença de espécies de importância ecológica e econômica, tornando esta área de especial relevância para a conservação. No entanto, é importante que os órgãos gestores cumpram seu papel no sentido de promover a efetividade de manejo da unidade, que inclui a elaboração do zoneamento ecológico-econômico, do plano de manejo e da aplicação de medidas eficazes de fiscalização e monitoramento da área.
The Areia Vermelha Marine State Park (Cabedelo Municipality, Paraiba State, Brazil) was established by the State Government to preserve the local biodiversity and to regulate touristic activities in the area. More than a decade after the creation of this park, we provide the first inventory of the benthic macrofauna of this single exclusively marine conservation unit in our State. Specimens were collected between February and April of 2008. Animals were sampled through intensive searches in the diverse microhabitats available on the reefs. A total of 102 species were identified belonging to Cnidaria (13 spp.), Mollusca (57 spp.), Crustacea (15 spp.), Echinodermata (15 spp.), and Ascidiacea (2 spp.). Fourteen out of these represent new occurrences for the coast of Paraiba State: Pennaria disticha, Encope emarginata, Aplysia dactylomela, Arene brasiliana, Hipponix leptus, Olivella nivea, Mancinella deltoidea, Notocochlis isabelleana, Pilsbryspira albocincta, Pilsbryspira zebroides, Cymatium cynocephalum, Mactrellona alata, Mactrotoma fragilis, and Mulinia cleryana. Three are endangered species according to the Brazilian legislation: Millepora alcicornis (hydrozoan coral), Echinaster (Othilia) echinophorus, and E. (O.) brasiliensis (sea stars). One species, the lobster Panulirus laevicauda, is considered over-exploited. Among the mollusks, Voluta ebraea and Turbinella laevigata are endemic to northeast Brazil; they are particularly vulnerable in the area of the park because of their relevance to the commerce of marine ornamental species. Our pilot study has revealed the presence of species of particular ecological and economic importance, confirming the special relevance of the studied area for conservation. It now becomes imperative that management entities delineate an efficient plan for the conservation and monitoring of this important conservation unit.
