Fishery and biometrics of genus Calappa crabs (Brachyura: Calappidae) in northeastern Venezuela. The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual land- ing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea, each represented 47% of the sample, and C. nitida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammea (1.9:1), while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcata is of great commercial interest, with average weight 290 g and a maximum weight of 720 g; C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and cara- pace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nitida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the animal is returned alive to the sea, for practical purposes a common equation among species and sexes to convert claws weight into total body weight is: total weight = 3 x claws weight. The relationship between catch per unit of effort (CPUE) and effort did not show a significantly decreasing trend, but landings follow the effort trend, with a decreasing tendency in recent years. No mature females were found in any of the three species, thus there could be reproductive migrations towards deeper waters from October to January, when abundance of crabs is lower in the study area. It is recommended that the practice of exploiting only one claw, returning the rest of the animal alive to the sea, should be promoted among fishers, while the removal of claws from female crabs should be avoided. Rev. Biol. Trop. 53(3-4): 463-474. Epub 2005 Oct 3.

Istiophorids are predators that are less abundant than many other species, and to study their life history, sufficient quantities are needed to draw inferences about their populations. In 199 1, the International Commission for the Conservation of Atlantic Tunas (ICCAT) Enhanced Research Program for Billfish sponsored a pelagic longline observer program in Venezuela on vessels targeting tuna and swordfish, and on artisanal vessels targeting bilifish, primarily to collect capture data and biological information on all istiophorid species. The Venezuelan Pelagic Longline Observer Program database from 1991 to 2000 was analyzed to provide life history characteristics of blue marlin Makaira nigricans, white marlin Tetrapturus albidus, and sailfish Istiophorus albicans from the eastern Caribbean Sea and adjacent waters. In blue marlin, the size distribution indicates a seasonal change between sex where different size-groups appear in the area most likely to feed and restore energy lost to spawning. White marlin shows spawning concentrations during the second quarter offshore north of La Hispaniola and Puerto Rico; off Venezuela, different size-groups were observed between seasons indicating a movement pattern between spawning and feeding grounds. Sailfish spawns off Venezuela's central coast from February to April and from June to September and off Surinam from February to September. Gross maturity estimates indicate that 50% of the population matures at 256.4 cm lower jaw Fork length in blue marlin, 189.9 cm LJFL in white marlin, and 180.2 cm LJFL in sailfish. Movement patterns based on tag-recaptured specimens seem to indicate Venezuelan waters serve as feeding grounds for blue marlin and white marlin and as spawning grounds for sailfish.

3 SUMMARY Catch rates from 1991 to 2004 for white marlin (Tetrapturus albidus) and blue marlin (Makaira nigricans) from the small scale fishery off La Guaira, Venezuela (a billfish hot-spot) were standardized by Generalized Liner Model techniques. The index of weight of fish per number of sets was estimated from dressed weight of marlins caught and reported by port sampling in the fishing community of Playa Verde. The analysis included the variables year and season (by quarters).

The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual landing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea. each represented 47% of the sample, and C. nitida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammnea (1.9:1). while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcuta is of great commercial interest, with average weight 290 g and a maximum weight of 720 g: C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and carapace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nitida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the animal is returned alive to the sea, for practical purposes a common equation among species and sexes to convert claws weight into total body weight is: total weight - 3 x claws weight. The relationship between catch per unit of effort (CPUE) and effort did not show a significantly decreasing trend, but landings follow the effort trend, with a decreasing tendency in recent years. No mature females were found in any of the three species, thus there could be reproductive migrations towards deeper waters from October to January, when abundance of crabs is lower in the study area. It is recommended that the practice of exploiting only one claw, returning the rest of the animal alive to the sea, should be promoted among fishers, while the removal of claws from female crabs should be avoided.

SUMMARY Indices of abundance of yellowfin tuna from the Venezuelan Pelagic Longline fishery are presented for the period 1991-2002. The index of number of fish per number of hook -hours fished was estimated from numbers of yellowfin tuna caught and reported in the Observer data forms recorded by scienti fic observers aboard longline (Pelagic Longline Observer Program) vessels since 1991. The standardization analysis procedure included the following variables; year, area, season, fishing time, and fishing depth. The standardized index was estimated using Generalized Linear Mixed Models under a delta lognormal model approach. RESUME

SUMMARY Indices of abund ance of yellowfin tuna (Thunnus albacares) from the Venezuelan pelagic longline fishery are presented for the period 1991-1999. The index of number of fish per number of hooks (hundred) was estimated from numbers of yellowfin tuna caught and reported on th e observer data forms recorded by scientific observers aboard longline vessels since 1991(Pelagic Longline Observer Program). Generalized additive models (GAMs) were applied to examine the relative influence of various factors on fishery performance defined as nominal CPUE of yellowfin tuna. The standardization analysis procedure included the following variables; year, area, season, fishing operation characteristics (main line length, hook density, target species), fishing time, and fishing depth. The standardized index was estimated using Generalized Linear Mixed Models under a delta lognormal model approach. RÉSUMÉ

SUMMARY Information on the spawning of yellowfin tuna (Thunnus albacares) from the western central Atlantic is updated from data collected in 1999. Spawning was analyzed based on oocyte development from ovary samples collected. Of the 133 ovaries used in the updated analysis, 1.5% (2 ovaries) of the sampled specimens were considered mature inactive, 2.3 % (3 ovaries) were considered maturing, 50.4% (67 ovaries) were identified as mature, 12% (16 ovaries) were considered ripe, 31.5% (42 ovaries) were identified as ready -to-spawn, and 2.3% (3 ovaries) were in spawned condition. Average batch fecundity for yellowfin tuna was estimated to be 2.1×10 6 oocytes (n=6), which ranged from 1.2×10 6 for a 132 cm FL (31.8 kg DWT) to 4.0 ×10 6 for a 142 cm FL (42.7 kg DWT) female. The average cost of a single spawning is about 0.83% of body weight. Spawning continues to take place in the Gulf of Mexico between May and August and in the southeastern Caribbean Sea between July and September.

Dolphinfish, Coryphaena hippurus, is a widely distributed epipelagic species that migrates seasonally in different areas of the oceans. In Venezuelan and adjacent waters it is fished commercially mainly by artisanal fishermen using surface longline and gillnet. Information on effort, location, catch at size, weight and sex determination from 1991 to 1997 was used to determine the seasonality of the demographic structure of dolphinfish off Venezuela. A total of 4876 specimens were measured and sexed from port sampling and observer-covered trips in longline vessels. Oocyte development and spawning season were estimated from samples collected in observer-covered trips on board longline vessels. The seasonality of dolphinfish off Venezuela appears to show two different size groups: one arriving at the end of the first quarter comprised of large mature individuals that will spawn in May, and one arriving at the beginning of the third quarter comprised of smaller specimens that will spawn in October-November. Sex ratio at size was significantly biased towards females in all quarters for smaller specimens (120 cm FL). Oocyte development revealed an indeterminate spawning pattern, as shown by the asynchronous oocyte development in the material examined. A reproductive strategy is proposed based on the seasonal movement pattern of dolphinfish off Venezuela, which is used to ensure recruitment success due to the prevailing environmental conditions off the Venezuelan coasts.

Twenty eight cephalopod species were identified from four survey cruises during 1988 in Venezuelan waters. The specimens were caught with a high opening bottom trawl and a pelagic "Harstad-trawl" type, at depths of 10 to 1,000 m. Fifteen species are recorded for the first time in the southern Caribbean and Venezuela.

SUMMARY This paper describes the activities carried out within the Enhanced Research Program on Billfish in Venezuela (PIIMV) during the January 2004-December 2005 period. During the aforementioned period, 20 trips were made in 2004 and 19 in 2005. These were monitored by PIIMV observers and represented a coverage rate of 12.2% for 2004 and 8.7% for 2005, of the total trips carried out by the Venezuelan longline fleet. Information is presented on billfish sampling, by species, on the catches from the vessels monitored. Port sampling at Playa Verde (La Guaira area) was conducted on 2,609 fishing trips in 2004 and 3,143 trips in 2005. A total of 10,300 sailfish, 2040 blue marlin, 1380 white marlin and 625 swordfish were sampled. Information is given on the billfish landings monitored at Margarita Island. As regards the billfish sport fishery, information is provided on the fishing tournaments carried out at the most important marina in Venezuela. There were 151 billfish tag recoveries for the entire period. The PIIMV provided essential support and logistics for studies on the reproductive dynamics of Tetrapturus species and for studies on age and growth of blue marlin and white marlin. RÉSUMÉ

SUMMARY Shark bycatch information is recorded from the Venezuelan Pelagic Longline Observer Program from 1994 to 2000. 21 shark species are caught by the Venezuelan longline fleet targeting tuna and swordfish as reported by scientific observers. Blue shark and blacktip shark represent 54.3% of the total shark catch in numbers, followed by smalltail shark, great hammerhead shark and the shortfin mako, which altogether they represent 23%. Blue shark catch at size data suggests a seasonal change in size in males and females. In contrast to the catch at size of blacktip shark that do not show distinct variations during the season. Seasonal distribution of blue shark is widely dispersed throughout the fishing grounds, in contrast to the blacktip shark in which the seasonal distribution is mostly concentrated in the Caribbean Sea. Overall catch at size and seasonal distribution is presented for each of remaining common species (i.e., smalltail shark, great hammerhead shark and the shortfin mako) . RÉSUMÉ