Syllidae (Annelida, Polychaeta) from the Caribbean coast of Venezuela

Venezuela possesses a great variety of coastal environments allowing for a high diversity of marine species. However, systematic studies on marine invertebrates are scarce, especially on polychaetes. The family Syllidae is poorly known, and only 14 genera and 42 species have been reported from this country. A total of 13 genera and 26 species the Syllidae were identified from benthic samples collected on different substrata of the northeastern coast of Venezuela. Of these, seven genera and 16 species constitute new records for Venezuela: Odontosyllis guillermoi, Syllides floridanus, Salvatoria clavata, Salvatoria limbata, Sphaerosyllis longicauda, Parapionosyllis longicirrata, Trypanosyllis parvidentata, Trypanosyllis vittigera, Opisthosyllis sp., Syllis amica, Syllis armillaris, Syllis gracilis, Syllis pseudoarmillaris, Syllis vittata, Parasphaerosyllis indica and Myrianida convoluta.     

Ichthyofauna associated to a shallow reef in Morrocoy National Park, Venezuela

Ichthyofauna associated to a shallow reef in Morrocoy National Park, Venezuela. Morrocoy National Park is one of the most studied coastal marine environments in Venezuela; however, efforts have been concentrated in south zone. In this study we select a shallow reef located in the north zone, characterized the benthic community and the structure of the fish community was studied using visual censuses. The benthic community was dominated by dead coral covered by algae (31%) and the live coral coverage was 12%. A total of 65 fish species belonging to 24 families were recorded, being Pomacentridae (43%), Scaridae (19%) and Haemulidae (15%) the most abundant families. Significant differences in the fish species abundances were found along the depth gradient, which could be related to the habitat characteristics, nevertheless herbivorous species dominance was evident at all depth strata. There seems to be a trend towards greater richness and density in the south zone reefs, and these differences may be related to the presence of extensive seagrass meadows and mangrove forests in that area or to differences in the recruitment patterns.     

Diversity patterns of arbuscular mycorrhizal fungi associated with cacao in Venezuela

The arbuscular mycorrhizal fungal (AMF) communities associated with cacao in Venezuela were studied. The species of AMF spores present in sixteen cacao plantations and in one nursery were isolated and identified when possible. The spore densities, species richness, diversity, Shannon-Wiener diversity index and dominance concentration index for the AMF communities were calculated. Acaulospora scrobiculata was associated with cacao plants in all study sites. No Scutellospora spp. were found in the analyzed soils. The spore number found in cacao plantations was relatively lower as compared with other tropical crops (38 spores 100 g^–1 soil up to 1674). Soils that were cultivated with cacao for more than 40 years showed the lowest spore numbers. Species richness and diversity of AMF communities associated with cacao, were negatively correlated with available P in soils. The Shannon-Wiener diversity index was positively correlated with soil organic matter. These results indicate that the traditional cacao cultivation practices used in Venezuela, maintain mycorrhizal infection on cacao plants. The diversity of the AMF community is similar to that found in natural undisturbed ecosystems from Venezuela.     

Marine Biodiversity of Aotearoa New Zealand

The marine-biodiversity assessment of New Zealand (Aotearoa as known to Māori) is confined to the 200 nautical-mile boundary of the Exclusive Economic Zone, which, at 4.2 million km², is one of the largest in the world. It spans 30° of latitude and includes a high diversity of seafloor relief, including a trench 10 km deep. Much of this region remains unexplored biologically, especially the 50% of the EEZ deeper than 2,000 m. Knowledge of the marine biota is based on more than 200 years of marine exploration in the region. The major oceanographic data repository is the National Institute of Water and Atmospheric Research (NIWA), which is involved in several Census of Marine Life field projects and is the location of the Southwestern Pacific Regional OBIS Node; NIWA is also data manager and custodian for fisheries research data owned by the Ministry of Fisheries. Related data sources cover alien species, environmental measures, and historical information. Museum collections in New Zealand hold more than 800,000 registered lots representing several million specimens. During the past decade, 220 taxonomic specialists (85 marine) from 18 countries have been engaged in a project to review New Zealand''s entire biodiversity. The above-mentioned marine information sources, published literature, and reports were scrutinized to give the results summarized here for the first time (current to 2010), including data on endemism and invasive species. There are 17,135 living species in the EEZ. This diversity includes 4,315 known undescribed species in collections. Species diversity for the most intensively studied phylum-level taxa (Porifera, Cnidaria, Mollusca, Brachiopoda, Bryozoa, Kinorhyncha, Echinodermata, Chordata) is more or less equivalent to that in the ERMS (European Register of Marine Species) region, which is 5.5 times larger in area than the New Zealand EEZ. The implication is that, when all other New Zealand phyla are equally well studied, total marine diversity in the EEZ may be expected to equal that in the ERMS region. This equivalence invites testable hypotheses to explain it. There are 177 naturalized alien species in New Zealand coastal waters, mostly in ports and harbours. Marine-taxonomic expertise in New Zealand covers a broad number of taxa but is, proportionately, at or near its lowest level since the Second World War. Nevertheless, collections are well supported by funding and are continually added to. Threats and protection measures concerning New Zealand''s marine biodiversity are commented on, along with potential and priorities for future research.     

A new species of Caligus (Copepoda, Siphonostomatoida) from the plankton of the Caribbean coast of Venezuela with a key to species

During a survey of the zooplankton community of Bahía Amuay, Venezuelan Caribbean, specimens of an undescribed species of Caligus Müller were collected. It resembles Caligus xystercus Cressey and Caligus ocyurus Cressey, both known only from the Caribbean Sea. The new species can be distinguished from these and other congeners by a combination of characters including the armature of legs 1 and 4, but mainly by its unique female genital complex. This is the first species of Caligus described from Venezuela. The species is described in full and a key to the species of the genus recorded in Venezuela is provided.     

Embrionary and larval development of Lytechinus variegatus (Echinoidea: Toxopneustidae) in laboratory conditions at Isla de Margarita-Venezuela

The sea urchin Lytechinus variegatus is a promissory species for aquaculture activities in tropical countries. In Venezuela, this species has some economical importance but their embryonic and larval development had not been studied. We collected specimens from seagrass beds in Margarita Island (Venezuela) and kept them in the laboratory, where they spawned naturally. With filtered sea water (temperature 28 degrees C, salinity 37 psu) and moderate aeration, the eggs and sperm were mixed (relation 1:100) and reached a 90% fertilization rate. The fertilization envelope was observed after two minutes, the first cellular division after 45 minutes and the prism larval stage after 13 hours. The echinopluteus larval stage was reached after 17 hours and metamorphosis after 18 days of planktonic life, when the larvae start their benthic phase.     

The genus Menisporopsis in Venezuela with the addition of M. anisospora anam. sp. nov. from a palm tree

Menisporopsis anisospora anam. sp. nov., found on decaying petiole of fallen leaves of Wettinia praemosa in a cloud forest in Venezuela, is described and illustrated. This is characterized by having heterosporous conidia (allantoid, fusiform, subsigmoid, sublunate, vermiform to irregular) with unequal sides, subtruncate or truncated at base, attenuate at apex, one-celled, hyaline with 2–4-setulae. Two other Menisporopsis species are recorded for the first time from Venezuela and a key to the described species is provided.     

Intestinal helminths of capybaras, Hydrochoerus hydrochaeris, from Venezuela

Quantitative parameters of intestinal helminth species and their potential relations to host characteristics in a population of capybaras (Hydrochoerus hydrochaeris) from Venezuela are reported for the first time. The intestines of 40 capybaras were collected during the 1992-annual harvest at Hato El Cedral. Six helminth species were found: 2 cestodes (Monoecocestus macrobursatum, M. hagmanni), 2 nematodes (Viannella hydrochoeri, Protozoophaga obesa), and 2 trematodes (Hippocrepis hippocrepis, Taxorchis schistocotyle). This is the first report for M. macrobursatum in Venezuela. Helminth abundance did not differ between sexes or age classes. Although patterns of distribution for all helminth species were overdispersed, the high prevalence found for all species (over 70%) and the high abundance observed for nematodes made it difficult to assess the effect that these helminths may produce on capybaras. Nevertheless, the negative associations found between the body condition of capybaras and helminth intensity for M. macrobursatum and V. hydrochoeri, might be pointing out potential host population regulatory role for these parasites which require further research.     

Taxonomy of some microteids (Squamata) from Venezuela, I: variation and geographic distribution of Euspondylus acutirostris and description of a new Euspondylus from northeast Venezuela

Only two species of the microteiid lizard genus Euspondylus (E. acutirostris and E. phelpsorum) had been reported from Venezuela. New records of the poorly known gymnophthalmid lizard Euspondylus acutirostris are reported extending its known range along the Coastal Range and Sierra de Aroa (north-central Venezuela) and Sierra de San Luis (northwestern Venezuela), all records occurring at the cloud forest above 1000 m. Seven body measurements were included and morphological variation is described based on at least 17 new specimens. Sexual dimorphism is determined in, at least, eight characteristics of size and squamation. Specimens were found in epiphytic bromeliads and the ground. The populations from Sierra de Aroa and Sierra de San Luis (only one specimen known from each locality), differ from those of the Coastal Range (supposedly the nominal population) in some morphological and coloration features, suggesting that the former two could represent different taxonomical entities. A new species of Euspondylus is described based on a female (taken within a bromeliad) from Cerro El Humo, Sucre, northeastern Venezuela. It differs from congeners mainly by having keeled scales on the limbs and a very acute snout.     

Population analysis using the nuclear white gene detects Pliocene/Pleistocene lineage divergence within Anopheles nuneztovari in South America

Anopheles (Nyssorhynchus) nuneztovari Gabaldón (Diptera: Culicidae), a locally important malaria vector in some regions of South America, has been hypothesized to consist of at least two cryptic incipient species. We investigated its phylogeographic structure in several South American localities to determine the number of lineages and levels of divergence using the nuclear white gene, a marker that detected two recently diverged genotypes in the primary Neotropical malaria vector Anopheles darlingi Root. In An. nuneztovari, five distinct lineages (1-5) were elucidated: (1) populations from northeastern and central Amazonia; (2) populations from Venezuela east and west of the Andes; (3) populations from Colombia and Venezuela west of the Andes; (4) southeastern and western Amazonian Brazil populations, and (5) southeastern and western Amazonian Brazil and Bolivian populations. There was a large amount of genetic differentiation among these lineages. The deepest and earliest divergence was found between lineage 3 and lineages 1, 2 and 4, which probably accounts for the detection of lineage 3 in some earlier studies. The multiple lineages within Amazonia are partially congruent with previous mtDNA and ITS2 data, but were undetected in many earlier studies, probably because of their recent (Pleistocene) divergence and the differential mutation rates of the markers. The estimates for the five lineages, interpreted as recently evolved or incipient species, date to the Pleistocene and Pliocene. We hypothesize that the diversification in An. nuneztovari is the result of an interaction between the Miocene/Pliocene marine incursion and Pleistocene climatic changes leading to refugial isolation. The identification of cryptic lineages in An. nuneztovari could have a significant impact on local vector control measures.     

Limosella subulata Ives (Scrophulariaceae) in Venezuela

DIAZ-MIRANDA, D., 1992. Limosella subulata Ives (Scrophulariaceae) in Venezuela.
Field and herbarium studies revealed that the genus Limosella is represented in Venezuela by a single species, Limosella subulata Ives. A distinct character of the Venezuelan material studied is the presence of 4-merous flowers, which has not been reported previously for this species.     

Spiniferites cruciformis: a fresh water dinoflagellate cyst?

Palynological studies of cored lacustrine sediments from the late Quaternary of Lake Kastoria, northern Greece, revealed a Late Glacial interval with abundant dinoflagellate cysts. Cyst assemblages include two identifiable species, Spiniferites cruciformis and Gonyaulax apiculata. The presence of the fresh water species G. apiculata is consistent with the lacustrine setting of these deposits, but that of S. cruciformis is anomalous. Previously, this species has only been recorded in abundance from presumed brackish marine sediments from the Black Sea and Marmara Sea sediments where geochemical data clearly record brackish salinities. Therefore, it has been regarded as a low salinity cyst type with a wide range of morphological variation that some workers have suggested to reflect salinity fluctuations. Specimens from Greece display only part of the range of morphological variability previously described from these (brackish) marine settings. Encountered morphological variation includes ellipsoidal/pentameral and cruciform endocyst shapes with rare intermediate shapes, and highly variable septa development. Specimens characterized by extremely reduced ornamentation known from (brackish) marine environments have not been recorded. Our records of S. cruciformis indicate that: (1) it could thrive in fresh water conditions; and (2) that apparently most of the strong morphological variations of the cysts are an intrinsic phenomenon for this taxon, and may only partly be linked to salinity variations as suggested earlier. We suggest that S. cruciformis essentially is a fresh water taxon, and that its records in (brackish) marine environments, with the exception of specimens with strongly reduced ornamentation, may be due to transportation, to short-lived fresh water surface conditions in such environments, or to tolerance of the species to brackish conditions.     

Treerunners,cryptic lizards of the Plica plica group (Squamata,Sauria, Tropiduridae) of?northern?South?America

The arboreal, Neotropical lizard Plica plica (Linnaeus, 1758) has been long considered a widespread species with a distribution east of the Andes. A preliminary examination of 101 specimens from about 28 locations mostly north of the Amazon suggests that Plica plica is a cryptic species complex with taxa that can be distinguished on the basis of the number of scale rows at mid-body; the arrangement, shape and ornamentation of scales on the snout; the number of lamellae on the fourth toe; the number of subocular plates; as well as other commonly used external morphological traits. The allopatric species discussed here are concordant with northern South American geography. Plica plica (Linnaeus, 1758) is associated with the Guiana Shield (Suriname, Guyana and Venezuela). A second species, P. caribeana sp. n. is associated with the Caribbean Coastal Range of Venezuela including Trinidad and Tobago. A third, distinctive species, P. rayi sp. n. is associated with the middle Orinoco at the eastern edge of the Guiana Shield. Two other species, P. kathleenae sp. n. and P. medemi sp. n., each based upon a single specimen, one from the Sierra Acarai Mountains of Guyana, and the other from southern Meta, Colombia are described. In addition to morphological analyses, we sequenced 12S and 16S rDNA gene fragments from one Plica plica from Trinidad to assess its relationship and taxonomy to other mainland Plica cf. plica. The results suggest Plica caribeana sp. n. likely diverged prior to the separation of Trinidad from northern Venezuela. Isolation in the Caribbean Coastal Range during its rapid uplift in the late Miocene, combined with a marine incursion into northern Venezuela may have contributed to their genetic divergence from other populations.     

Distribution and density of two holothurian species in Cubagua Island, Venezuela

Holothurian populations in the Caribbean have been significantly depleted in some areas, and others are still in danger to satisfy international markets. In Venezuela, this marine resource has been illegally exploited since the early 1990s. To contribute with their management and protection, this work analyzed the distribution, abundance and population structure of two commercial holothurians Isostichopus badionotus and Holothuria mexicana in Cubagua Island shores. A total of 52 stations were studied around the island during the year 2008. Surveys included visits to each station, for which a band transect of 50 m2 with four replicates were carried out. The results show that I. badionotus has a higher distribution on the East coast of the island, and is found over Thalassia testudinum beds or bivalve molluscs aggregations, with an average density of 0.011 ind/m2, C.I. 95% = 0.005-0.017, n = 122, and a general abundance estimated in 117 ind/ha. H. mexicana has been practically depleted (0.001 ind/m2 C.I. 95% = 0.0002-0.0013, 7.7 ind/ha, n = 8). We recommend the maintenance of the total ban adopted in 1997 to assure the protection of these species, mainly because no previous data supported the start of the fishery, and also, because the current densities are still very low when compared to other areas in Venezuela and the Caribbean. These are animals easy to catch, susceptible to overfishing, and with a very low recovery rate; thus, more control is required from the local authorities.     

Biogeographical affinities among Neotropical cloud forests

 Biogeographical affinities among cloud forests in the Neotropical region were studied through a track approach, by constructing generalised tracks based on the results of a parsimony analysis of endemicity (PAE). Distributional data on 946 genera and 1,266 species of vascular plants (Pteridophyta, angiosperms, and gymnosperms) from 26 cloud forest patches from Colombia, Costa Rica, Cuba, Honduras, Jamaica, Mexico, Peru, Puerto Rico, and Venezuela were analysed; and four localities from eastern and western United States were also included as outgroups. The track analysis identified six generalised tracks: a first one that includes the majority of the cloud forests of Mexico, Central America, the Antilles, and northern Colombia; a second one that includes southern Mexico and northern Central America; a third one that includes the mountains in northwestern South America; a fourth one that includes the mountains in southwestern South America; and two others in western and eastern United States. It is concluded that the Neotropical cloud forests are closely related and that those of the Caribbean subregion exhibit complex relationships, which could be due to the complex tectonic history of the area. Received February 22, 2001 Accepted May 1, 2001     

Patterns of Freshwater Fishes of the Caribbean Versant of Venezuela

We delineate local and regional biogeographic provinces that suggest patterns of species richness, and primary and secondary freshwater fish distributions along the Caribbean coast of Venezuela. We use presence‐absence records and classification and ordination models. Patterns at local and regional scales varied markedly such that primary species dominated humid drainages and secondary species dominated arid drainages or transition provinces. Species rich areas, and the presence of narrowly endemic species correlate with patterns of historical isolation and hydrographic refuges. Patterns of species distributions across arid drainages suggest that close proximity of coastal marine drainages allows dispersion and exchange of species. This pattern is particularly evident among secondary species. Hotspots of species richness and endemisms are identified and are recommended as priorities for conservation (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A new species of Tityus (Scorpiones: Buthidae) from Turimiquire, Venezuela

We describe a new species of Buthid scorpion, Tityus quirogae, from the Turimiquire mountains, eastern side of the La Costa range, Monagas and Sucre States, Venezuela. It is morphologically similar to T. nematochirus and T. meridanus. It differs from these species in the distribution of the dorsal femoral trichobothria and in the following combination of characters: (1) I caudal segment with two parallel ventral keels. Caudal segments II to IV with ventral keels that are double in the extremes of the segments and single in the middle, (2) noticeable sexual dimorphism, especially in pedipalp shape; the male chelae are markedly thin and long, (3) number of pectineous teeth (male: 18 in each pecten; female: 18 in the right pecten and 19 in the left one), and (4) number of denticle rows in the movable finger of the right chela (16 in both sexes). T. quirogae is the first species of this genus, in the Northeastern region of Venezuela, with thin and elongated pedipalps.     

Common Distribution Patterns of Marsupials Related to Physiographical Diversity in Venezuela

The aim of this study is to identify significant biotic regions (groups of areas with similar biotas) and biotic elements (groups of taxa with similar distributions) for the marsupial fauna in a part of northern South America using physiographical areas as Operational Geographical Units (OGUs). We considered Venezuela a good model to elucidate this issue because of its high diversity in landscapes and the relatively vast amount of information available on the geographical distribution of marsupial species. Based on the presence-absence of 33 species in 15 physiographical sub-regions (OGUs) we identified Operational Biogeographical Units (OBUs) and chorotypes using a quantitative analysis that tested statistical significance of the resulting groups. Altitudinal and/or climatic trends in the OBUs and chorotypes were studied using a redundancy analysis. The classification method revealed four OBUs. Strong biotic boundaries separated: i) the xerophytic zone of the Continental coast (OBU I); ii) the sub-regions north of the Orinoco River (OBU III and IV); and those south to the river (OBU II). Eleven chorotypes were identified, four of which included a single species with a restricted geographic distribution. As for the other chorotypes, three main common distribution patterns have been inferred: i) species from the Llanos and/or distributed south of the Orinoco River; ii) species exclusively from the Andes; and iii) species that either occur exclusively north of the Orinoco River or that show a wide distribution throughout Venezuela. Mean altitude, evapotranspiration and precipitation of the driest month, and temperature range allowed us to characterize environmentally most of the OBUs and chorotypes obtained.     

A single origin for the limnetic–euryhaline taxa in the Corbulidae (Bivalvia)

The bivalve family Corbulidae, known colloquially as ‘basket clams’, includes species tolerating a wide variety of habitats ranging from open marine to freshwater. Previous studies of corbulid phylogenetics have been based mainly on shell morphology and to some extent soft tissue anatomy. However, these studies have been inadequate for corbulid classification because of difficulties in determining the inter‐relationships of primarily marine species with non‐marine species, the latter commonly exhibiting highly divergent morphological, ecological and environmental characteristics from their marine counterparts. The first molecular phylogenetic study of the Corbulidae is presented herein, analysing DNA sequences from the 18S rRNA and 28S rRNA genes, separately and in combination. Fifteen corbulid species and 14 outgroup taxa were included in the analyses. Corbulidae is resolved as monophyletic, comprising three groups with varying support. The non‐marine species form one group that we name as the subclade ‘limnetic–euryhaline Corbulidae’ (LEC) and comprising the genera Lentidium, Erodona and Potamocorbula. This LEC, which is consistently recovered as monophyletic, is globally distributed. The marine Corbulidae are divided into two well‐supported lineages in combined analyses although there are inconsistencies in their membership between single‐gene analyses. One of the two lineages consists of primarily Western Pacific taxa and the other of North American and Caribbean taxa. Finally, the authors advocate further study on the LEC to mitigate potential biological invasions beyond their native distribution.