Oscar M. Lasso-Alcalá

Invasion of the Indo-Pacific blenny Omobranchus punctatus (Perciformes: Blenniidae) on the Atlantic Coast of Central and South America

We examined 308 specimens of the Indo-Pacific blenniid Omobranchus punctatus deposited in four museum collections, and analyzed data on their collection locations to assess its invasion on the Atlantic coast of Central and South America. This species occurs in shoreline estuarine and marine habitats in the Indo-West Pacific. Previous sampling and recent records in the Tropical West Atlantic from 1930 to 2004 produced 20 records for: Panama, Colombia, Venezuela, Trinidad and Brazil. In this work, we provide data on 17 new records for the Gulfs of Venezuela and Paria in Venezuela, as well as four records for Maranhao and Para states in NE Brazil. The temporal pattern of collections (1930 - 2009) and the proximity of most localities to ports and zones of ship traffic indicate that O. punctatus was initially introduced to the Atlantic by ships travelling from India to Trinidad. Within Brazil the introduction is linked to shipping connected to petroleum platforms. In Maranhao and Para the

Noteworthy new records of squamate reptiles (Reptilia: Squamata) from various Venezuelan Caribbean islands, including a new addition to the herpetofauna of Venezuela

The occurrence of Gymnophthalmus lineatus in Venezuela is established for the first time based on a specimen collected on Las Aves Archipelago. We also document the first records of Phyllodactylus ventralis from Los Frailes Archipelago, Amphisbaena alba from Isla de Margarita, and report the occurrence of Thecadactylus cf. rapicauda on Las Aves Archipelago. Additionally we expand the distribution of the snake Leptophis ahaetulla on Isla de Margarita and report the third specimen known from that island. We also present information on the lepidosis and coloration for all species when pertinent.

GEOGRAPHIC DISTRIBUTION OF TWINHORN BLENNY, CORALLIOZETUS CARDONAE (ACTINOPTERYGII: PERCIFORMES: CHAENOPSIDAE), WITH NEW RECORDS FROM THE SOUTHERN CARIBBEAN

The twinhorn blenny, Coralliozetus cardonae Evermann et Marsh, 1899, i s currently known from the Caribbean Sea and adjacent waters, with the exception of the Gulf of Mexico, Florida, Bermuda, and the coast and islands to the north of Venezuela. In this work we report for the first time its occurrence at 19 stations from the Venezuelan coast, Curacao, and Bonaire Island (Netherlands Antilles), in the Southern Caribbean, based on the examination of 155 specimens. In addition, we provide information on the meristic, distinctive characters, a nd habitat of this species.

Redescription of Trichomycterus striatus (Meek & Hildebrand, 1913) (Siluriformes: Trichomycteridae), with notes on its geographic distribution

Trichomycterus striatus is herein redescribed, based on examination of the types and recently collected specimens, and its geographic distribution is updated. This species can be diagnosed from all other northeastern South American congeners by its variable coloration pattern consisting of a yellowish to light brown background with a black lateral band and/or small dark brown spots on sides or uniformly light brown and by the following combination of characters: teeth conical arranged in three to four irregular rows in both jaws; anterior section of infraorbital canal (sensory pores i1 and i3) present; sensory pores s6 paired, 11-23 opercular odontodes; 27-44 interopercular odontodes; seven to eight pectoral-fin branched rays; 36-37 free vertebrae; 12-14 ribs; cleithrum pierced by several foramina; and caudal fin truncate to rounded. Trichomycterus striatus occurs from southern Costa Rica [from the Pirrís (herein reported for the first time), Térraba and Coto River basins] to eastern Panama (in most of the main river basins in both the Pacific and Atlantic versants), being the sole representative of the family in lower Central American waters.

Biodiversity and Conservation of the Estuarine and Marine Ecosystems of the Venezuelan Orinoco Delta

1.1 Oceanographic features and eco-regions of the Orinoco Delta The Orinoco is one of the largest rivers in South America (2,150 Km). Globally, it is the third in water flow (yearly average of 39,000m3/s), and the fifth in sediment transportation (150 million tons/year). The Orinoco basin extends for nearly a million square kilometers within Colombian and Venezuelan territories, and is characterized by at least ten large terrestrial and aquatic eco-regions including its opening into the Atlantic through the vast Orinoco Delta (located between 07° 46 to 10° 00 N, and 59° 50 to 62° 35 W) (Michelangeli, 2000; Bone et al., 2004; Lasso et al., 2010). These deltaic plains were formed by the combined action of sediment and freshwater discharges from the Orinoco, with the tides on a flat alluvial plain (Miloslavich et al., 2011) creating a dynamic ecosystem of fluvial and estuarine habitats. The boundaries between these two habitats are defined according to their altitude above sea level and tidal influence (Lasso & Sanchez-Duarte, 2011), with the fluvial delta corresponding to the mid and high delta according to Cervigon (1985). The lower limit of the fluvial delta varies due to seasonal annual fluctuations in freshwater discharge from the Orinoco, related to regional and, even local, precipitation regimes, and a salt wedge from the sea that moves inward with the incoming tide. In the estuarine delta, the ecological boundary of the fluvial delta is the limit at which the sea water influences the main stream and its channels, while the ecological boundary with the sea is a fringe, which is variable in size and forms after sand or mud bars at the opening of the seaward channels. Along this longitudinal zone from the upper to the lower delta, a geomorphological, physico-chemical, and therefore, biological gradient can be observed. In addition to this longitudinal gradient, a very important transversal gradient also exists, that creates particular lentic ecosystems with specialized biota. Within the Atlantic, the major areas of influence of the Orinoco are (1) the Gulf of Paria, a semi-enclosed area between the Araya Peninsula (Venezuela) and the