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Leonardo Francisco Machado, Áthila Bertoncini Andrade, Maurício Hostim-Silva and João Pedro Barreiros: Habitat use by the juvenile dusky grouper Epinephelus marginatus and its relative abundance, in Santa Catarina, Brazil, pp. 133-138
The
dusky grouper (Epinephelus marginatus) is a species whose stock management
deserves special attention. It has an important role in hard-bottom ecosystems
and, as a protogynous hermaphrodite; it is especially susceptible to
overfishing. Data on the species÷ use of habitat, and on the way environmental
and behaviour parameters influence its abundance can help to improve management
and conservation strategies. The aim of this study was to evaluate the
influence of bottom type, temperature and species behaviour on the abundance of
E. marginatus,
using a quadrat for visual census. An area of 80 m2, divided between
rocky shore, rocky outcrop and sandy habitats was surveyed monthly. Densities
of juveniles were: 1.16 groupers m-2 over the rocky shore and 1.47
groupers m-2 over the rocky outcrop, while no groupers were found
over sand. Analysis of the yearly variation in abundance revealed a migratory
pattern of dispersal and gathering. All size groups observed in this study were
below the first maturation length.
Wilson J. E. M. Costa, Cristiano R. Moreira and Flávio C. T. Lima:
Simpsonichthys cholopteryx n. sp. (Cyprinodontiformes: Rivulidae: Cynolebiatinae): a new dwarf annual fish from the upper Rio Araguaia basin, central Brazil, pp. 139-144
Simpsonichthys
cholopteryx n.
sp., collected in the upper Rio Araguaia basin, central Brazil, is described.
It belongs to a clade that includes S. boitonei and S. parallelus, diagnosed by the absence of
pelvic fin and girdle. The new species is considered to be a sister group to S.
parallelus, both
sharing apomorphic colour patterns of the caudal fin and iris in males, small
adult size and absence of teeth on the second pharyngobranchial. It differs
from S. boitonei and S. parallelus in the colour patterns of the flank and unpaired fins in
males, and by having more anal fin rays in females.
Jeffrey
T. Williams and Julie H. Mounts: Descriptions of six new Caribbean fish species
in the genus Starksia (Labrisomidae), pp. 145-164
Extensive
collecting efforts using rotenone sampling throughout the Caribbean over the
past four decades have vastly increased the numbers of specimens of cryptic
fishes in museum collections. Among these specimens, we discovered
representatives of six new cryptic fish species belonging in the Starksia
fasciata and S.
sluiteri species
complexes. Descriptions are provided herein for the following new species: S.
leucovitta from
Navassa Island; S. melasma from Mona Island, Puerto Rico, and Buck Island Reef National
Monument, St. Croix; S. multilepis from Fernando de Noronha Island and Atol das Rocas, Brazil;
S. rava from
Tobago, Trinidad and Tobago; S. sella from Tobago, Trinidad and Tobago, all in
the S. sluiteri
complex; and in the S. fasciata complex, S. smithvanizi from Buck Island Reef National Monument
(St. Croix), Navassa Island, St. Barthelemy, and Dominica. Starksia fasciata is restricted in distribution to
the Bahamas and northern Cuba. We provide an identification key and diagnostic
characters for the 21 western Atlantic species (those species in the S.
ocellata complex
are diagnosed only in the key). The descriptions herein bring the total number
of recognized western Atlantic species of Starksia to 21.
Thelma
L. P. Dias and Ierecê L. Rosa: Habitat preferences of a seahorse species, Hippocampus
reidi
(Teleostei: Syngnathidae) in Brazil, pp. 165-176
The
habitat preferences of Hippocampus reidi are reported, based on the first field
study of a seahorse population in the western south Atlantic. Data on holdfasts
used by juveniles and adults were obtained in north-east Brazil between October
2000 and December 2001, during four-hour daily underwater observation sessions
over a period of 45 days. The random visual census method was used while
snorkelling or scuba diving. Occurrences of seahorses on each holdfast were
recorded on an underwater slate, filmed and photographed. H. reidi used a total of 18 different
holdfasts, of which the green algae Caulerpa racemosa and C. kempfi, the tunicate Ascidia nigra, and the roots of the mangrove
plants Avicennia schaueriana and Rhizophora mangle were the most frequent. H. reidi was also found in crevices or
leaning against the muddy bottom. While using the holdfasts, H. reidi were seen feeding (mostly young
individuals) or engaging in courtship behaviour. During tidal shifts, they were
seen moving with the tide, apparently not engaged in any particular activity.
The results of the present study suggest that strategies to conserve seahorse
populations in Brazil should emphasize habitat conservation. The algae of the
genus Caulerpa constitute
one of the most important holdfasts for H. reidi in the study area, both for juveniles
and adults.
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