Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This study evaluated the environmental impact on water quality in a small-scale trout farming facility. The parameters measured were pH, dissolved oxygen (DO), total dissolved solids (TDS), total suspended solids (TSS), color, turbidity, biochemical oxygen demand (BDO5), ammonia nitrogen (N-NH4), nitrate (N-NO3), nitrite (N-NO2), and thermotolerant coliforms. The quality of the water after being used by the farming facility did not exceed the values measured upstream. The physical, chemical and microbiological analyses of the water showed that trout activities do not significantly affect the water quality when compared with the upstream and downstream sampling points of the fish farm. Results showed that the water load used on the trout farm was 148 m3 kg-1 , similar to values observed worldwide. The flow rate used by the trout farm, along with a conventional decantation system, were responsible for maintaining the water quality. In general, the results indicate that small trout farming facilities can be attractive from an economic point of view, with low environmental impact.

Large-bodied animals, megafauna, are disproportionately threatened and yet, remain relatively difficult to monitor, particularly true in the ocean. Consumer-grade drones have high definition imagery and offer a non-invasive way to monitor a subset of marine megafauna, especially those species that spend part of their life near the water’s surface. However, a key question is the extent to which drone imagery data offer reliable abundance estimates due to potential detection restraints, and the ability to compare data from different locations. Here we tested the efficacy of a quadcopter drone to collect megafauna abundance data in multiple shallow-water habitats in the realistic background variation of shoreline development. On Great Abaco Island, The Bahamas we repeated drone surveys in nearshore habitats from June to August 2015 at three paired high and low human population sites. We tested the drone's detection probability using decoy organisms and found no effect of water quality or benthic characteristics on detectability. In short, the drones appear to work to monitor these species. We also noted patterns in the occupancy of the species on which we focused. We observed three shark, two ray, and two sea turtle species, finding higher abundances of all species in our low human population sites compared to high human population sites. Our results highlight the ability of consumer-grade drones to estimate the abundance and distribution of large-bodied elasmobranchs and sea turtles in shallow water habitats. Further, our study supports their capability to evaluate issues related to the conservation and management of nearshore ecosystems.

The deep-sea crab Chaceon ramosae occurs at 350-1200 m depth in the southeast and south of Brazil. Here we evaluated the latitudinal, bathymetric, and seasonal abundance of C. ramosae in southern Brazil obtained during several research cruises. We also obtained populational data to evaluate the effectiveness of the fishing regulations for C. ramosae. Five sampling cruises were carried out in 2009-2010 and the sampling effort comprised 32 fishing hauls with four pots per mainline. In total, 195 individuals were caught, 128 males and 67 females, of which 17 were ovigerous. The highest catch per unit effort occurred between 29°03’ and 29°05’S at 800-1000 m in depth. The highest abundance occurred in winter, and almost all ovigerous females were captured in this season. The size at the onset of sexual maturity was estimated at 120 mm carapace width. Depth was the most critical environmental factor explaining C. ramosae distribution. The largest individuals, as well as the mature ones, were mainly captured in shallower regions (400-600 m). Our results confirm the need for prohibiting the fishing for C. ramosae at depths lesser than 500 m.

The native fish Dormitator latifrons, also known as Chame, Popoyote, Puyeque and Pacific fat sleeper, grows in brackish environments in estuaries of the American Pacific coast, from Baja California, in Mexico, to Perú. It is consumed regionally and its characteristics under culture conditions are currently being evaluated. This study compared the proximate composition and fatty acid profile of wild and cultured specimens of D. latifrons in order to determine the effect of feeding them a commercial diet for tilapia under culture conditions. The protein content of the muscle of wild fish was higher than that of cultured fish, but the total lipid content was lower. The levels of fatty acids C18:1n9 and C18:2n6 were significantly higher (P

The external morphology of the larval steps in the development of the Anomuran crab Allopetrolisthes punctatus is described using material obtained under laboratory conditions and from field samples. All stages are presented with photos taken with a scanning electron microscope. For the first time in this species, and in a similar way as described for the whole family Porcellanidae, it was possible to identify one prezoea, two zoeal and one megalopa stages. The main difference between the zoeal stages is the translucid spine in the center of the telson of the zoea II, surrounded by five gross setae at each side. Also, we also studied first juvenile stages to know the size at which sexual pleopods appear, which in our samples it occurred at 1.97 mm of carapace length.

The purpose of this study was to characterize histopathological changes induced by the sea louse Caligus rogercresseyi in juvenile individuals of rainbow trout (Oncorhynchus mykiss). Specific effects were determined for mucus-secreting cells, mast cells/eosinophilic granule cells (MCs/EGCs) and activation of pro-inflammatory caspase-1, which are involved in the inflammatory response. As expected, C. rogercresseyi eroded the skin to varying degrees, with increased mucussecreting cells in the epidermis and melanophores in the dermis. Gill responses included epithelial hyperplasia, secondary lamellae fusion, an increased quantity of mucus-secreting cells in the epithelium, and MCs/EGCs in the connective tissue. Other histological changes included abundant MCs/EGCs and secretory cells in the intestine, as well as numerous melano-macrophage centres in head kidney stroma cells. Finally, the observed inflammatory response was associated with active caspase-1 detection in the gills, but not in the other assessed organs. In conclusion, C. rogercresseyi induced significant histopathological alterations in O. mykiss skin and gills and minor histological changes in the intestine and head kidney, which may reflect the overall inflammatory response of rainbow trout to infestation with sea lice.

Biofloc system is an alternative to conventional aquaculture systems as it minimizes effluents, improves water quality, ensures greater biosafety due to minimal water exchanges and also serves as an additional food source for prawn. The present study aimed to evaluate the effect of suppression of vitamin and mineral supplements on diets for Macrobrachium rosenbergii reared in the biofloc system. Four experimental diets were evaluated: complete diet (Diet 1 with vitamin and mineral supplementation); diet without vitamin supplement (Diet 2); diet without mineral supplement (Diet 3) and diet without vitamin and mineral supplement (Diet 4). The experimental design was completely randomized with four replicates per treatment. After 45 days of trial survival rates above 90% and feed conversion rate ~1.83 were observed for all treatments, indicating that the production of M. rosenbergii in the biofloc system does not require the inclusion of vitamin and mineral supplementation in the feed.

Penaeid trawls are poorly selective fishing gears; contributing towards approximately 27% of global marine fisheries discards. Various options are available for mitigating penaeid-trawl bycatch, including gear modifications such as ‘bycatch reduction devices’ (BRDs) or codend mesh-size regulations. A precursor to developing modifications is information about the key target and bycatch species in terms of their sizes and morphology. Here we describe the relationships between these characteristics for the southern Brazilian industrial penaeid-trawl fishery within a broader objective of proposing more selective trawl configurations. Catches were sampled during 37 tows. Fifty-two species were caught, including two loggerhead turtles, Caretta caretta, one green turtle, Chelonia mydas, as well as 61 individuals of seven ray species classified as Endangered or Critically Endangered. One penaeid (Pleoticus muelleri) and 11 teleosts were assessed for various morphological relationships. The data demonstrated that both the existing conventionally used 26 mm (stretched mesh opening; SMO) mesh and a legislated size of 30 mm SMO are too small. Using morphological relationships, we propose testing a minimum diamond-shaped mesh size of at least 35 mm and a square-mesh window in the top of the codend comprising at least 48 mm mesh. Such a configuration would probably retain penaeids and larger teleosts, but allow many small teleosts to escape. Anteriorly located grids are also required to reduce the bycatch of charismatic species like turtles and rays. Wide-scale use of such BRDs should considerably reduce bycatches and the ancillary impacts of regional penaeid-trawl fisheries. 

Mexican snook (Centropomus poeyi) is one of the most important commercial species in Southeast Mexico, which has been overexploited by fisheries. For this reason, some recent studies related to its culture have been done. However, the basic biological knowledge of the digestive physiology is still unknown. In this study, the gene expression of trypsin, (TRY), bile-salt dependent lipase (BAL), amylase (AMY), and cytosolic non-specific dipeptidase (CNP) was investigated during the larval period from embryo (0 days after hatching, DAH), eleuteroembryo (1 DAH) until 25 DAH using RTq-PCR approach and was normalized with the elongation factor 1-α gene (EF1-α). TRY gene expression showed the maximum peak at 17 DAH; meanwhile, BAL gene expression showed variations during larviculture, however, three peaks were observed at 10, 17 and 25 DAH, which appears to correspond to changes in live food supply (rotifers and Artemia nauplii). AMY gene expression was low detected from hatching onwards and showed a slight peak at 10 DAH when larvae were fed with Artemia nauplii. Finally, CNP gene expression had presented three peaks at 2 DAH (yolksac absorption), 19 and 23 DAH when larvae were fed with Artemia nauplii. We conclude that C. poeyi larvae showed early and high digestive enzyme expressions, especially TRY, which indicate that could be possible to start the weaning process at 25 DAH, which could be shorter compared than other Centropomid species.