Species of dinoflagellates of the genus Gambierdiscus (Dinophyceae) in the Mexican Caribbean Sea

Some dinoflagellates with benthic habits are related to ciguatera intoxication by fish consumption, especially in tropical areas. In the Mexican Caribbean, ciguatera is relatively common, but only one paper seems to have been published on the subject, and there are very few publicactions on phytoplankton and benthic microalgae. Material collected along the coast of the State of Quintana Roo with phytoplankton net (54 mm) and directly from sediment and epiphytes of macroscopic plants, was searched for toxic and other associated dinoflagellates. Samples were studied by light and scanning electron microscopy. Morphological characters were useful for species identification, but eventually physiological, ecological and molecular characters could also be used. Three species of Gambierdiscus, related to the production of ciguatera toxins, were identified: G. belizeanus, G. toxicus and G. yasumotoi. They are distributed in shallow coastal areas, including coastal lagoons.     

Echinoderms (Echinodermata) of the Mexican Caribbean

A systematic list of the echinoderms of the Mexican Caribbean based on museum specimens of the Colección Nacional de Equinodermos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México and the National Museum of Natural History, Smithsonian Institution, Washington, D.C. is presented. This list reveals an important echinoderm biodiversity in the Mexican Caribbean, where five of the six echinoderm classes are represented. A total of 178 echinoderm species is recorded, distributed in 113 genera, 51 families and 22 orders. 30 new records for the Mexican Caribbean are presents: Crínoidea (three), Asteroidea (two), Ophiuroidea (eleven), Echinoidea (one), Holothuroidea (thirteen).     

A new species of Monstrilla (Copepoda: Monstrilloida) from a reef lagoon off the Mexican coast of the Caribbean Sea

From plankton samples taken at a Caribbean reef lagoon off the eastern coast of the Yucatan Peninsula, an undescribed species of a monstrilloid copepod belonging to the genus Monstrilla was collected. The new species is distinguished from the other species of the genus by the structure and proportional length of the antennulae, by the particular features of the spiniform genital process, and by its size. The new species constitutes the fourth report of the genus Monstrilla in the eastern coast of the Yucatan Peninsula.     

The composition and distribution of benthic amphipods (Crustacea: Amphipoda) in the southern Barents Sea

The composition and distribution of near-bottom amphipods in the southern part of the central Barents Sea were studied based on quantitative materials collected by expeditions of the Murmansk Marine Biological Institute in 1996–1997. A total of 144 amphipod species (on average 13 ± 1 species per station) were found; the average biomass was 0.49 ± 0.07 g/m², average abundance 106 ± 15 specimens/m². Boreal-Arctic (46%), Arctic (17%), and boreal (21%) species were predominant among the amphipod fauna. The present results were compared with the data for 1968–1970.     

Exogoninae (Polychaeta: Syllidae) from the Mexican Caribbean region with a key for the Gran Caribbean species]

This paper identifies the Exogoninae (Syllidae) from the Mexican Caribbean coasts and includes a key to identify all the species recorded from the Grand Caribbean Sea. The classification of the family and the composition of Exogoninae are briefly examined; the correct names of the subfamilies are Syllinae Grube, 1850, Eusyllinae Malaquin, 1893, Autolytinae Malaquin, 1893 and Exogoninae Langerhans, 1879. Exogoninae includes Anguillosyllis Day, 1963, Brania de Quatrefages, 1866, Braniella Hartman, 1963, Exogone ?rsted, 1845, Exogonella Hartman, 1961, Exogonoides Day, 1963, Parapionosyllis Fauvel, 1923, Psammosyllis Westheide, 1990, Spermosyllis Claparède, 1864, and Sphaerosyllis Claparède, 1863. Pseudexogone Augener, 1922, formerly included in the group, is not a syllid; it belongs to Pilargidae. We collected 814 specimens belonging to 3 genera, 3 subgenera and 13 species as Brania (4), Exogone (4) and Sphaerosyllis (5); five new species are described: Brania russelli n. sp, Brania uebelackerae n. sp, Brania westheidei n. sp., Exogone (Exogone) bondi n. sp. and Exogone (Parexogone) sanmartini n. sp. For each species, selected references, diagnostic features, observations on morphological variability, distribution and illustrations are provided; new species also have an english diagnosis. Most abundant species were B. uebelackerae n. sp. (295), S. taylori Perkins (169), E. (E.) dispar Webster (76), and E. (E.) bondi n sp. (72).     

A new species of Caprella (Crustacea: Amphipoda) from the Mediterranean Sea

A new caprellid amphipod, Caprella tavolarensis n. sp., is described based on specimens collected from a Posidonia oceanica seagrass meadow at the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, Mediterranean Sea). The species is close to Caprella liparotensis, but can be clearly distinguished by smaller size, presence of a short rostrum, body elongate and dorsally smooth, absence of serrate carina on the basis of gnathopod 2 and pereopods, mouthparts scarcely setose, absence of fine setae on peduncle of antenna 1 and absence of swimming setae on antenna 2. The number of caprellid species reported from the Mediterranean Sea has increased from 23 (1993) to 41 (2010), consequently, further taxonomical studies should be addressed to properly estimate the total amphipod diversity in the Mediterranean Sea.     

Novel eukaryotes from the permanently anoxic Cariaco Basin (Caribbean Sea)

Present knowledge of microbial diversity is decidedly incomplete (S. J. Giovannoni and M. S. Rappé, p. 47-84, in D. Kirchman, ed., Microbial Ecology of the Oceans, 2000; E. Stackebrandt and T. M. Embley, p. 57-75, in R. R. Colwell and D. J. Grimes, ed., Nonculturable Microorganisms in the Environment, 2000). Protistan phylogenies are particularly deficient and undoubtedly exclude clades of principal ecological and evolutionary importance (S. L. Baldauf, Science 300:1703-1706, 2003). The rRNA approach has been extraordinarily successful in expanding the global prokaryotic record (S. J. Giovannoni and M. S. Rappé, p. 47-84, in D. Kirchman, ed., Microbial Ecology of the Oceans, 2000; E. Stackebrandt and T. M. Embley, p. 57-75, in R. R. Colwell and D. J. Grimes, ed., Nonculturable Microorganisms in the Environment, 2000) but has rarely been used in protistan discovery. Here we report the first application of the 18S rRNA approach to a permanently anoxic environment, the Cariaco Basin off the Venezuelan coast. On the basis of rRNA sequences, we uncovered a substantial number of novel protistan lineages. These included new clades of the highest taxonomic level unrelated to any known eukaryote as well as deep branches within established protistan groups. Three novel lineages branch at the base of the eukaryotic evolutionary tree preceding, contemporary with, or immediately following the earliest eukaryotic branches. These newly discovered protists may retain traits reminiscent of an early eukaryotic ancestor(s).     

Novel Eukaryotes from the Permanently Anoxic Cariaco Basin (Caribbean Sea)

Present knowledge of microbial diversity is decidedly incomplete (S. J. Giovannoni and M. S. Rappé, p. 47-84, in D. Kirchman, ed., Microbial Ecology of the Oceans, 2000; E. Stackebrandt and T. M. Embley, p. 57-75, in R. R. Colwell and D. J. Grimes, ed., Nonculturable Microorganisms in the Environment, 2000). Protistan phylogenies are particularly deficient and undoubtedly exclude clades of principal ecological and evolutionary importance (S. L. Baldauf, Science 300:1703-1706, 2003). The rRNA approach has been extraordinarily successful in expanding the global prokaryotic record (S. J. Giovannoni and M. S. Rappé, p. 47-84, in D. Kirchman, ed., Microbial Ecology of the Oceans, 2000; E. Stackebrandt and T. M. Embley, p. 57-75, in R. R. Colwell and D. J. Grimes, ed., Nonculturable Microorganisms in the Environment, 2000) but has rarely been used in protistan discovery. Here we report the first application of the 18S rRNA approach to a permanently anoxic environment, the Cariaco Basin off the Venezuelan coast. On the basis of rRNA sequences, we uncovered a substantial number of novel protistan lineages. These included new clades of the highest taxonomic level unrelated to any known eukaryote as well as deep branches within established protistan groups. Three novel lineages branch at the base of the eukaryotic evolutionary tree preceding, contemporary with, or immediately following the earliest eukaryotic branches. These newly discovered protists may retain traits reminiscent of an early eukaryotic ancestor(s).     

Egg size and composition in Ceratoserolis (Crustacea: Isopoda) from the Weddell Sea

Summary Samples of ovigerous female Ceratoserolis trilobitoides carrying newly spawned (stage A1) eggs in the marsupium were obtained from Borge Bay; Signy Island (South Orkney Islands), the continental shelf near Elephant Island (South Shetland Islands), and two sites in the inner Weddell Sea. The dry mass of a newly spawned egg was greater at the inner Weddell Sea sites even when the larger size of the females from the Weddell Sea and the positive relationship between egg size and female size were taken into account. Larger eggs contained more yolk, and there was a slight but significant tendency for larger eggs to have a lower percentage nitrogen content. Eggs from Ceratoserolis meridionalis were smaller in size than sympatric Ceratoserolis trilobitoides, but of similar composition. The reason for a greater investment per egg by females at higher latitudes is not clear, but it may be related to a slightly longer development period, itself associated with the lower water temperatures in the inner Weddell Sea.Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation     

Siphonophores of upwelling areas of the Campeche Bank and the Mexican Caribbean Sea

The siphonophore fauna off the Yucatan Peninsula and in the Mexican Caribbean Sea remains practically unknown. This communication describes the composition, abundance and distribution of Siphonophora during summer 1984 and spring 1985. The local distribution and abundance of siphonophores were found to be strongly influenced by upwellings, especially during the spring survey. Community analysis suggests that siphonophore populations around the upwellings are relatively homogeneous.     

Community structure of caprellids (Crustacea: Amphipoda: Caprellidae) on seagrasses from southern Spain

The community structure of caprellids inhabiting two species of seagrass (Cymodocea nodosa and Zostera marina) was investigated on the Andalusian coast, southern Spain, using uni and multivariate analyses. Three meadows were selected (Almería, AL; Málaga, MA; Cádiz, CA), and changes in seagrass cover and biomass were measured from 2004 to 2005. Four caprellid species were found; the density of Caprella acanthifera, Phtisica marina and Pseudoprotella phasma was correlated to seagrass biomass. No such correlation was found for Pariambus typicus, probably because this species inhabits sediments and does not cling to the seagrass leaves. We recorded a significant decrease in seagrass cover and biomass in MA due to illegal bottom trawling fisheries. Phtisica marina and P. typicus were favoured by this perturbation and increased their densities after the trawling activities. A survey of reports on caprellids in seagrass meadows around the world showed no clear latitudinal patterns in caprellid densities (ranging from 6 to 1,000 ind/m² per meadow) and species diversity. While caprellid abundances in seagrass meadows are often very high, the number of species per meadow is low (range 1–5).     

Distribution and diversity of the Syllidae (Annelida: Polychaeta) from the Mexican Gulf of Mexico and Caribbean

The objective of this study was to contribute to the knowledge of the syllids distributed in the eastern coasts of Mexico (Gulf of Mexico and Caribbean) taking into consideration their composition, distribution and diversity. Sampling was done at 77 stations including 49 in soft bottoms (terrigenous and carbonate sediments), and 28 in hard bottoms (coralline substrates) sampled in nine reef zones included in three reef systems (Veracruz, Campeche and Cozumel). In all 2084 individuals were collected (13.5% in soft sediments and 86.4% in coralline areas). Forty-five species were identified: 31 in soft bottoms and 38 in corals, with 21 species common to both types of environments. In soft bottoms, the highest species richness and diversity were found in the Carbonate Zone, while syllids were uncommon in the Terrigenous Zone. In hard bottoms, the highest density, species richness and diversity values were found in the Veracruz Reef System, followed by the Campeche Bank and Cozumel Island Reef Systems. The dominant species in soft bottoms were Haplosyllis spongicola, Exogone lourei, Typosyllis cornuta and T. papillosus, whereas T. alosae, T. corallicola, T. cornuta and H. spongicola dominated in hard bottoms. The importance and success of the syllids in both soft bottoms and reef environments, particularly in those of the Gulf of Mexico is emphasized.     

Spatial structure of the Caribbean lobster (Metanephrops binghami) in the Colombian Caribbean Sea

Crustaceans of the genus Metanephrops are of great commercial value in some tropical and subtropical regions. With the potential development of a new deep lobster fishery in the Colombian Caribbean Sea, the objective of this work is to describe for first time the patterns of spatial and bathymetric distribution, and diel migratory periodicity of the Caribbean lobster (M. binghami). Data were collected by trawling in depths between 200 and 550 m (100 m strata intervals) in the Colombian Caribbean Sea. Higher biomass and size of these crustaceans were found between 250 and 350 m, with a maximum at about 300 m. The study offers diel patterns of M. binghami, which suggests nocturnal activity and burrowing during daylight hours.     

New record of Lithodidae (Crustacea Decapoda, Anomura) from the Antarctic (Bellingshausen Sea)

During the Bentart-2003 Cruise, carried out during austral summer 2003 in the Bellingshausen Sea, three species of Lithodidae, Paralomis birsteini, Lithodes murrayi and Neolithodes capensis, were caught from 218 m to 1947 m. With these captures the presence of L. murrayi in Peter I Island is confirmed, the distribution area of N. capensis is greatly increased and the captures of N. capensis and P. birsteini represent the first lithodid record known from the Antarctic continental slope. Also, these records show large and discontinuous distributions, which illustrate that many distribution patterns of Antarctic species are more an artefact of limited studies than representing actual distribution.     

Necrotic patches affect Acropora palmata (Scleractinia: Acroporidae) in the Mexican Caribbean.

An outbreak of necrotic patches was observed affecting Acropora palmata in the Mexican Caribbean in the summer of 1999. This study documents the tissue loss produced by these patches. Following a marked initial increase in the number of patches, there was a decrease in the appearance of new patches but the size of the patches increased throughout the study. In some cases patches expanded but in most cases they enlarged due to fusion of 2 or more patches. Patches recovered but not sufficiently to overcome damage in most colonies surveyed. Percentage tissue loss does not appear to be directly related to temperature but may be related to a combination of factors associated with prolonged summer doldrum-like conditions. The necrotic patch syndrome can have a substantial impact in tissue loss in affected A. palmata colonies.     

Hurricane impact on Thalassia testudinum (Hydrocharitaceae) beds in the Mexican Caribbean

Hurricanes have increased in strength and frequency as a result of global climate change. This research was conducted to study the spatio-temporal distribution and changes of Thalassia testudinum, the dominant species in Bahia de la Ascension (Quintana Roo, Mexico), when affected by heavy weather conditions. To complete this objective, a 2001 Landsat ETM+ image and the information from 525 sampling stations on morpho-functional and coverage of T. testudinum were used, and the seeds generated for the classification of eight benthic habitats. To quantify the changes caused by two hurricanes, we used two images, one of 1988 (Gilberto) and another of 1995 (Roxanne); other three data sets (2003, 2005 and 2007) were also used to describe the study area without major weather effects. Six categorial maps were obtained and subjected to analysis by 8 Landscape Ecology indexes, that describe the spatial characteristics, structure, function, change of the elements (matrix-patch-corridor), effects on ecosystems, connectivity, edges, shape and patch habitat fragmentation. Models indicate that T. testudinum may be classified as a continuum (matrix), since the fragments were not observed intermittently, but as a progression from minimum to maximum areas in reference to their coverage (ecological corridors). The fragments do not have a regular shape, indicating that the impacts are recent and may be due to direct effects (high-intensity hurricanes) or indirect (sediment). Fragments of type "bare soils" have a discontinuous distribution, and are considered to be the sites that have remained stable over a long timescale. While more dense coverage areas ("beds", "medium prairie" and "prairie") have low fragmentation and high connection of fragments. Features have an irregular perimeter and radial growth of formal; suggesting that the impact of meteors has no effect on the resilience of T. testudinum in this ecosystem, indicating good environmental quality to grow in this bay.     

A spawning aggregation of Nassau grouperEpinephelus striatus (Pisces: Serranidae) in the Mexican Caribbean

Synopsis An annual spawning aggregation of Nassau grouper,Epinephelus striatus, observed off the southern coast of Quintana Roo, Mexico, on full moon days in December and January, was surveyed during the winters from 1991 to 1993. A fish aggregation had been appearing at one traditional site off Mahahual for more than 80 years, but currently it forms at undetermined sites far from the original site. Fish migration was northwards in the fore reef border along the 14 m isobath and isolated groups were observed. Through visual assessment fish aggregations were found to include 200 to 500 individuals. The fishing on Nassau grouper aggregations has been active since 1910 by using hook and line; however, recently fishermen used gill nets. It is necessary to continue the research on this aggregation and establish management guidelines to protect the species.