Instituto Oceanografico Of Venezuela

Cumaná, Venezuela

Instituto Oceanografico Of Venezuela

Cumaná, Venezuela
Time filter
Source Type

Rangel M.S.,Southern Cross University of Australia | Mendoza J.,Instituto Oceanografico Of Venezuela | Freites L.,Instituto Oceanografico Of Venezuela | Tagliafico A.,Southern Cross University of Australia | Silva J.,Instituto Oceanografico Of Venezuela
Molluscan Research | Year: 2016

The pen shell Atrina seminuda is a target for a small artisanal Caribbean fishery; however, little is known about its biology. The length frequency distribution, biometric relations and reproduction of this species were studied in northeastern Venezuela. Using transects selected from among 360 stations a population was sampled monthly by SCUBA diving. An analysis of 1748 individuals showed a shell height (SH) between 4 cm and 23.6 cm, with an average of 16.7 ± 2.5 cm. For both sexes, statistical differences in mean SH were observed (analysis of variance F (1, 1113) = 69.538; P < 0.001); organisms larger than 22 cm were females, whereas those between 8 and 10 cm were males. Log-linear regressions were estimated for shell length (SL), total weight (TW) and adductor muscle weight (MW) as a function of SH. In all cases there were statistical differences between males and females, with males presenting positive allometry and females showing isometry. Mean SH at maturity for males (8.24 cm) was lower than for females (11.88 cm), and for sexes combined was estimated at 8.71 cm. Gametogenic activity was observed throughout the year, with two main peaks of spawning (April and August/September 2008). All this information is crucial for demographic modelling and stock assessment for managing this species. © 2016 The Malacological Society of Australasia and the Society for the Study of Molluscan Diversity

Gonzalez A.,Instituto Limnologico UDO | Mendoza J.,Instituto Oceanografico Of Venezuela Udo | Arocha F.,Instituto Oceanografico Of Venezuela Udo | Marquez A.,Instituto Oceanografico Of Venezuela
Zootecnia Tropical | Year: 2012

We evaluated the level of exploitation of Pseudoplatystoma fasciatum in the Caicara-Cabruta Orinoco sector using the analytical model of Thompson and Bell and the length of the fish landed by the main fishing port in the region between January 2007 and December 2008. Total mortality Z was determined by different methods: catch curve, Beverton and Holt and Sssentongo and Larkin while natural mortality M was calculated using the empirical equations by Pauly, Rikhter and Efanov, Srinath and Alverson and Carney. The values of Z and M used to estimate the rate of exploitation and application of the Thompson and Bell model were selected by using the averages and confidence intervals obtained from each method. Maximum sustainable yield (MSY) and fishing mortality F was established from the yield per recruit curve, using the benchmark F0.1. Biomass per recruit and spawning biomass per recruit was also determined using as reference points F50% and F40%, respectively. Z values were between 0.31 (0.29 to 0.34) according Beverton and Holt and 0.35 (0.34-0.37) according Ssentongo and Larkin while M ranged from 0.12 (0.11 to 0.14) according Srinath and 0.24 (0.22 to 0.26) according Pauly. According to the values of exploitation rate and F estimated in the different scenarios analyzed in the current conditions of capture of P. fasciatum in the Caicara-Cabruta Orinoco sector the species is between heavily exploited and overexploited, requiring the implementation of restrictive measures for proper management.

Diaz-Diaz O.,Instituto Oceanografico Of Venezuela | Rios B.,University of the East Venezuela
Pan-American Journal of Aquatic Sciences | Year: 2014

Syllidae is the best known family of polychaetes in Venezuela with 60 species recorded belonging to 15 genera. In this note, Proceraea anopla (Monro, 1933) is reported for the first time for both Venezuela and the southern sector of the Grand Caribbean region, increasing the knowledge of the biodiversity of the family for the region.

Semidey D.,University of the East Venezuela | Marquez A.,University of the East Venezuela | Lodeiros C.,University of the East Venezuela | Lodeiros C.,Instituto Oceanografico Of Venezuela
Zootecnia Tropical | Year: 2010

Growth and survival of juvenile pearl mother Pinctada imbricata was evaluated through six months of culture in suspended hanging ropes and pearl nets using a longline in Turpialito Bay, Cariaco Gulf, Venezuela. Pearl oyster seeds 15 mm long were cultured, evaluating survival, shell length, muscle, rest of the body and byssus mass monthly. Variations of salinity, temperature, chlorophyll a, seston, solved oxygen and shell fouling, were determined every two weeks. After six months, the oyster reached dorso-ventral length close to 50 mm. Shell growth pattern was similar for both types of culture, although byssus mass was higher in hanging ropes, while shell length was greater in pearl nets. No significant differences were found in body mass. Survival showed similar patterns in both culture systems, although a decrease in numbers occurred in January for the oysters in pearl nets, associated to the presence of the gastropod Cymatium sp. The phytoplanktonic biomass was positively correlated to growth in P. imbricata, showing to be an important factor in growth modulation. The results suggest the use of the rope system for the culture of P. imbricada.

Gonzalez A.,University of the East Venezuela | Mendoza J.,Instituto Oceanografico Of Venezuela | Arocha F.,Instituto Oceanografico Of Venezuela | Marquez A.,Instituto Oceanografico Of Venezuela
Zootecnia Tropical | Year: 2015

The big catfish genus Brachyplatystoma are among the species of greatest economic importance of fisheries at the Orinoco basin in Venezuela, but until now no related studies of biology or stock are known. This lack of knowledge hampers the implementation of strategies for conservation and sustainable use of the resource; determinants in this study the age and growth of the golden catfish Brachyplatystoma rousseauxi in Caicara-Cabruta region Orinoco River, as basic information for the evaluation of this important resource. The study was done using the direct method of reading the growth rings of the pectoral spine, which showed ages ranging between two and five years old, with a predominance of fish in two years, and growth parameters estimated back calculate lengths from the formation of each ring, with values of L∞= 130 cm in total length and K = 0.233 año-1. These values indicated a relatively low growth rate and high longevity that place B. rousseauxi between those species susceptible to fishing activities, which requires strict management measures for conservation. © 2015, Instituto Nacional de Investigaciones Agricolas (INIA). All rights reserved.

Mengual M.,University of the East Venezuela | Lodeiros C.,University of the East Venezuela | Lodeiros C.,Instituto Oceanografico Of Venezuela | Marquez A.,University of the East Venezuela
Zootecnia Tropical | Year: 2011

The winged oyster Pteria colymbus is distributed in western Atlantic, from North Carolina to south of Brazil. Juveniles of P. colymbus of 32 mm (dorso-ventral axis) were cultivated in cylinders made from plastic net, suspended at 1,5 m in a long line in the Bahía de Mochima, Sucre state. Once a month, survival and shell length was determined, as well as the mass for the shell, muscle and rest of body parts. Additionally, temperature, salinity, dissolved oxygen, seston and phytoplanktonic biomass was determined in the location. The different body parts showed differential growth patterns during the experimental period, due to different energetic demands needed for their production and the availability of energy sources in the environment. At the end of the experiment, P. colymbus increased in dorso-ventral length and total tissue mass in 68 and 390%, respectively. The growth of the tissue mass was not exponential, showing growth only in the last months, which suggests that the oysters were under stress conditions induced by the low phytoplankton availability and high temperatures. The low observed growth, along with the low final survival (30%) allows to determine that the studied area is not suitable for the culture of this species, than can be performed in other areas of eastern Venezuela such as Cariaco Gulf.

Moreno C.,Instituto Nacional Of Investigaciones Agricolas | Graziani C.,University of the East Venezuela | Nunez J.G.,Instituto Oceanografico Of Venezuela | Villaroel E.,University of the East Venezuela
Zootecnia Tropical | Year: 2011

The development of a fishery industry in any country requires biological, ecological and marketing studies about the natural source to be exploited. In this sense, decapods crustaceans in the communities of Punta Araya, Chacopata and Playa Patilla in Sucre State-Venezuela were studied for thirteen months. A total of 1826 crabs, belonging to 7 families, including 16 species and 1 subspecies, were collected. Crab biodiversity, equivalence, abundance, dominance, permanence and affinity amongst the 3 localities, as well as the gender proportion and population recruitment of the 3 main crab species present at each locality were analyzed. Crab total biodiversity was 1,22 bits/ind., equivalence oscillated between 0,16 y 0,85; abundance varied from 0,27 to 1,36. The species Callinectes ornatus was the unique species constantly found on the communities studied and also the more abundant on each locality; showing an average value of 79,63% and a gender proportion of 1:1. The average crabshells length and biomass were 65,12 mm ± 22,03 and 20,91g ± 18,87, respectively; both parameters showed higher for the male than female gender. A comparison of the growth equation obtained indicate that C. ornatus has a major alometric growth with recruitment all over the year but showing two main peaks on March and October. The physic-chemical parameters were similar for the three localities studied, except during the upwelling periods where the phytoplankton blooms providing higher food availability not only for crab larvae development but also for many other organisms. The crab C. ornatus might become an important element of basic fisheries that could contribute to improve the socio-economic status of the fishery communities settled on the east coast of Venezuela; however, it is necessary to carry out additional biological studies in order to achieve potential steady fisheries.

Noel L.B.,Instituto Oceanografico Of Venezuela | Yelipza L.R.,University of the East Venezuela | Acosta V.,University of the East Venezuela | Parra B.,Instituto Oceanografico Of Venezuela
Zootecnia Tropical | Year: 2012

Channel flyer Dactylopterus volitans is a fish that posses great commercial attractiveness mainly due to its muscle quality, this is why studying its biometrics is very important in order to regulate its exploitation. In present study a total of 345 specimens were examined. Fish were collected monthly from March 2002 to March 2003. The population sample was constituted by organisms of different size groups with a range between 71 and 363 mm total length (TL), with the highest percentage for the size class between 120-200 mm TL. The relative growth of the species was characterized by generally not be uniform, as some relationships majorant showed allometric growth (body width vs. total length: 4,013***), others had minorante allometric growth (head length vs. total length: -6,144*).). The species D. volitans introduced an isometric length-weight relationship, registering no change in Kn per month or by size groups.

Yelipza L.R.,University of the East Venezuela | Acosta V.,University of the East Venezuela | Parra B.,Instituto Oceanografico Of Venezuela | Lista M.,University of the East Venezuela
Zootecnia Tropical | Year: 2011

We examined a total of 504 specimens of Hemirhamphus brasiliensis, which were collected monthly from march 2002 to march 2003 around the island of Cubagua. In these organisms were evaluated size composition, morphometric and relative growth, length-weight relationship and relative condition factor. The organisms studied were adults, mostly consisting of 333 females (66.08%), 99 males (19.64%) and 72 indeterminate organisms (14.2%). The average standard length for females was 281.88 mm with variation between 216 and 330 mm for males ranged between 217 and 330 mm with an average of 277.91 mm, while for juveniles or undetermined sex ranged from 206 to 320 mm with an average of 247.82 mm, being the most common sizes of 257 and consist of 313 mm of Lst. The relationship between standard length and morphometric studies indicate that different parts of the body have minorante allometric growth. No significant differences were found for the slopes between females, males and indeterminate. The analysis of length-weight relationship showed a highly significant positive relationship between both variables, a growth minorant alometric. Mean Kn values were equal or close to 1, reflecting the good physiological condition of fish in the study area.

Lemus M.,University of the East Venezuela | Lemus M.,Instituto Oceanografico Of Venezuela | Rojas N.,University of the East Venezuela | Rojas-Astudillo L.,University of the East Venezuela | Chung K.,Instituto Oceanografico Of Venezuela
Revista de Biologia Tropical | Year: 2013

Metallothionein is a cytosolic protein found in a variety of tissues and have been involved in the regulation of essential trace metals such as copper and zinc, and in the detoxification of essential and nonessential metals. With the aim to study their seasonal variation and their possible role in reproductive behavior, we evaluated metallothioneins (Mts) in Perna viridis, taken from Rio Caribe and Chacopata localities in the North coast of Sucre state, Venezuela. A total of 325 samples were obtained from February to December 2003. We determined the following biometric indices in bivalves: Condition Index (CI), meat yield (RC) and dry weight-length relationship (PSL). Besides, Mts in whole tissue were separated by molecular exclusion chromatography, Sephadex G-50 and quantified by saturation with cadmium. Our results showed that the biometric indices (RC and PSL) had seasonal variations between localities and maturity stages, with the exception of IC. No significant differences were found between sexes. Mts showed seasonal variations between localities, with the highest concentrations between February and March, and minimum ones between September and December, coinciding with the respectively high and low productivity periods in the area. The mussels from Rio Caribe had higher Mts concentration than those from Chacopata. Furthermore, immature mussels showed the highest Mts concentration while the lowest was found in spawned specimens. We found a significant negative relationship between Mts and CI. Our results demonstrated that MTs in Perna viridis are influenced by the condition index and reproductive status, as well as physico-chemical factors in the marine environment.

Loading Instituto Oceanografico Of Venezuela collaborators
Loading Instituto Oceanografico Of Venezuela collaborators