RESUMO
Free-living bryozoans, unlike most cheilostomes, live unattached from the substratum on or within soft sedimentary bottoms. Bryozoans of the family Cupuladriidae Lagaaij, 1952 are probably the best-studied free-living representatives. In Brazil, eight species of cupuladriids have been reported to date, including some regarded as species complexes. This paper documents cupuladriid taxa from northeastern and northern Brazil based on the examination of 1236 colonies. Three species previously reported from Brazil are described: Cupuladria monotrema (Busk, 1884), Discoporella gemmulifera Winston Vieira, 2013 and Discoporella salvadorensis Winston, Vieira Woollacott, 2014. A new species, Cupuladria minuta n. sp., is erected; it differs from its congeners in having small, flat discoid colonies, with the central area up to the fifth astogenetic generation composed of vicarious avicularia with an auriform opesia, and quadrangular to rectangular basal sectors with 1-6 small openings per sector. Our results suggest that four species previously recorded from Brazil are doubtful-Cupuladria canariensis (Busk, 1859), Cupuladria biporosa Canu Bassler, 1923, Discoporella umbellata (Defrance, 1923) and Discoporella depressa (Conrad, 1841). Some Brazilian specimens previously assigned to Discoporella umbellata var. conica are re-assigned to D. salvadorensis. The species studied here frequently co-occur on mainly sandy and muddy bottoms at 8-130 m depth, as it is typical of most living populations of cupuladriids. The sedimentation rate, and thus the bottom composition, likely influence the distribution of cupuladriids in Brazil, with Cupuladria species being more common in stabler and coarser sea bottoms than Discoporella species, which tend to be more broadly distributed.
Assuntos
Briozoários , Animais , BrasilRESUMO
Biological and abiotic processes influence ecosystem structure and species distribution. For bryozoan assemblages, depth, substratum and habitat structure are among the main factors influencing their distribution. Ecological studies on bryozoan fauna from Brazil are scarce and factors affecting the distribution and/or diversity of this common group are obscure. Here we attempted to verify the influence of bathymetry on bryozoan richness on the north shore of Bahia State, north-eastern Brazil. We identified 57 bryozoan taxa, comprising 35 families and 50 genera, all belonging to the Cheilostomata. Retevirgula multipunctata Winston, Vieira & Woollacott, 2014 and Tetraplaria dichotoma (Osburn, 1914) and the genus Aimulosia Jullien, 1888 were recorded for the first time from Bahia State. Species growing as encrusting sheets were dominant at all depths. There was a significant difference in richness among samples at different depths, with highest values of richness at 40 meters (Kruskal-Wallis Test). Analysis of similarities revealed a significant difference among the bryozoan assemblages, mainly when comparing assemblages from 10 and 20 meters with deeper ones. Also, shallower assemblages composition varied much than assemblages from 30 and 40 meters. Since depth is a proxy for several environmental parameters, further studies are needed to identify other factors influencing bryozoan distribution.
Assuntos
Biodiversidade , Ecossistema , Brasil , HumanosRESUMO
As sessile organisms, bryozoans are among the commonest components of the encrusting communities on hard substrata. On unconsolidated bottoms, benthic animals and their carapaces, including mollusk shells, represent potential surfaces for encrustation. Here we describe the bryozoan fauna growing on disarticulated bivalve shells collected intertidally on Itaparica beach, Todos os Santos Bay, northeast Brazil. We examined a total of 382 valves representing seven species of bivalves, among which we found 82 valves of three bivalve species to be encrusted by bryozoans, with 109 bryozoan colonies detected overall. We identified 11 cheilostome bryozoan species, among which Phidoloporidae and Smittinidae were the most diverse, with four and two species, respectively. We redescribed two bryozoan species, Parasmittina loxoides and Rhynchozoon phrynoglossum, and describe another two, Pleurocodonellina marcusi n. sp. and Rhynchozoon itaparicaensis n. sp., as new. A new combination for Cribella triangulata Canu Bassler, 1928 is proposed, including Calyptotheca tenuata Harmer, 1957 as a new junior subjective synonym of Calyptotheca triangulata n. comb. All but one of the 11 species have encrusting colonies; Licornia aff. diadema, forms erect branching colonies. For seven of the bryozoans, ours are the first records of these species growing on shells. Although the majority of bryozoans we studied have also been reported on other substrata, Rhynchozoon brasiliensis and Parasmittina loxoides were predominant in the fauna, comprising 79 (72%) of all colonies inventoried. Due to the lack of information on the distribution of these species in northeastern Brazil, further studies are needed to determine whether they show any substratum preference.
Assuntos
Briozoários , Animais , Baías , Bivalves , BrasilRESUMO
A new species of the erect cheilostome bryozoan Cellaria Ellis & Solander, 1786 is described from Bahia, NE Brazil. Cellaria oraneae sp. nov. is the first formally characterized species of the genus reported from Northeastern coast of Brazil, distinguished from all congeners by the combination of hexagonal autozooids and rhomboid fertile zooids, hexagonal interzooidal avicularium with sagittate foramen, completely immersed ovicell with oval aperture and proximal rectangular lip. A brief discussion of the diversity of Cellaria from the Atlantic Ocean and a tabular identification key to these species are also provided.(AU)
Assuntos
Animais , Briozoários/anatomia & histologia , Briozoários/classificação , Fauna Marinha/classificação , Especificidade da Espécie , Brasil , Oceano AtlânticoRESUMO
A new species of the erect cheilostome bryozoan Cellaria Ellis & Solander, 1786 is described from Bahia, NE Brazil. Cellaria oraneae sp. nov. is the first formally characterized species of the genus reported from Northeastern coast of Brazil, distinguished from all congeners by the combination of hexagonal autozooids and rhomboid fertile zooids, hexagonal interzooidal avicularium with sagittate foramen, completely immersed ovicell with oval aperture and proximal rectangular lip. A brief discussion of the diversity of Cellaria from the Atlantic Ocean and a tabular identification key to these species are also provided.
Assuntos
Animais , Briozoários/anatomia & histologia , Briozoários/classificação , Fauna Marinha/classificação , Brasil , Especificidade da Espécie , Oceano AtlânticoRESUMO
Here we present the taxonomy of the cheilostome genera Adeonellopsis MacGillivray, 1886 and Reptadeonella Busk, 1884 in Brazil. Of the six species previously reported in Brazilian waters, we include redescriptions of Adeonellopsis subsulcata (Smitt, 1873), Reptadeonella bipartita (Canu & Bassler, 1928) and Reptadeonella costulata (Canu & Bassler, 1928). Four new species of Reptadeonella are described: Reptadeonella aspera n. sp., Reptadeonella brasiliensis n. sp. (previously misidentified as Reptadeonella violacea), Reptadeonella cucullata n. sp. and Reptadeonella leilae n. sp. Reptadeonella aspera n. sp., from Bahia State, is characterized by rugose frontal calcification, a tubular peristome, small suboral avicularium and elliptical spiramen. Reptadeonella brasiliensis n. sp. is the commonest intertidal species in NE Brazil; it is distinguished from other Brazilian Reptadeonella in having a nodular peristome, large subperistomial areolar pore and zooids with one or two frontal pores frequently replaced by a suboral avicularium and crescentic spiramen. Reptadeonella cucullata n. sp., from Espírito Santo and Bahia states, has a hood-like peristome, large subperistomial areolar pore, suboral avicularium with curved mandible and denticulate spiramen. Reptadeonella leilae n. sp., described from Bahia State, has a frontal shield with small granules, tubular peristome, semilunar to semicircular subperistomial areolar pore and circular spiramen. Diagnostic characters of Reptadeonella species are discussed.
Assuntos
Briozoários/anatomia & histologia , Briozoários/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Brasil , Briozoários/crescimento & desenvolvimento , Tamanho do ÓrgãoRESUMO
Bryozoans constitute an important component of marine-fouling communities of anthropogenic substrata. Many species have been reported as exotic or widespread around the world, typically in ports and harbors of non-polar regions. Here we present the first record of a species of the bryozoan Triphyllozoon in the Atlantic Ocean. Triphyllozoon arcuatum (MacGillivray, 1889), described originally from Australia, is reported herein from natural substrata in Singapore and natural and artificial substrata in Brazil. Although easily recognizable, the species has not been previously reported from anywhere else in the Atlantic. In the latter instance, the species was collected during monitoring of the invasive scleractinian corals Tubastraea spp. on an oil platform originally from Singapore and now located at Todos os Santos Bay, northeastern Brazil. Colonies of T. arcuatum were also found associated with three species of sponges, giving evidence that it is also growing in the natural environment. Todos os Santos Bay is characterized by intense commercial shipping traffic and oil exploration and the finding of T. arcuatum on an oil platform provides strong evidence that it represents a non-indigenous species in the Atlantic. Owing to the possible impact of T. arcuatum in Brazil, further studies and monitoring of its bioinvasion are recommended.(AU)
Assuntos
Animais , Briozoários/anatomia & histologia , Biodiversidade , Oceano AtlânticoRESUMO
Bryozoans constitute an important component of marine-fouling communities of anthropogenic substrata. Many species have been reported as exotic or widespread around the world, typically in ports and harbors of non-polar regions. Here we present the first record of a species of the bryozoan Triphyllozoon in the Atlantic Ocean. Triphyllozoon arcuatum (MacGillivray, 1889), described originally from Australia, is reported herein from natural substrata in Singapore and natural and artificial substrata in Brazil. Although easily recognizable, the species has not been previously reported from anywhere else in the Atlantic. In the latter instance, the species was collected during monitoring of the invasive scleractinian corals Tubastraea spp. on an oil platform originally from Singapore and now located at Todos os Santos Bay, northeastern Brazil. Colonies of T. arcuatum were also found associated with three species of sponges, giving evidence that it is also growing in the natural environment. Todos os Santos Bay is characterized by intense commercial shipping traffic and oil exploration and the finding of T. arcuatum on an oil platform provides strong evidence that it represents a non-indigenous species in the Atlantic. Owing to the possible impact of T. arcuatum in Brazil, further studies and monitoring of its bioinvasion are recommended.
Assuntos
Animais , Biodiversidade , Briozoários/anatomia & histologia , Oceano AtlânticoRESUMO
Two new species of cheilostome bryozoans are described from Bahia and Espírito Santo States, Brazil-Calyptooecia conuma n. sp. and Hippotrema fissurata n. sp. Both genera are registered for the first time in the South Atlantic Ocean. Inter alia, Calyptooecia conuma n. sp. is characterized by the presence of dimorphic brooding zooids with relatively small orifices and no perioral tubercles, contrasting with bigger non-brooding zooids having larger orifices surrounded by perioral tubercles. Hippotrema fissurata n. sp. differs from congeners in colony morphology and colour, in details of the ooecium and in zooidal metrics. Specimens were collected on varied substrata, commonly calcareous nodules and shells as well as other bryozoans and sponges.