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

A pair of juvenile emperor penguins (Aptenodytes forsteri) was observed in the northern coast of James Ross Island, the north-western sector of the Weddell Sea, Antarctica, in January 2017. The penguins originated from the colony located on Snow Hill Island, 120-130 km far from the observation area. Despite the emperor penguin´s ability to migrate over long distances, when they are well-known from different areas in Antarctica, this was the first observation of this species in the north of James Ross Island. In this short paper we discuss the environmental factors which allowed the penguins to reach James Ross Island northern coast, especially significant sea ice variability in this area during last decade.

Abstract.- This study provides baseline information on the feeding habits of five batoid species from the genera Mobula and Myliobatis sampled from the small-scale driftnet fishery in northern Peru. The diets of Mobula mobular, Mobula munkiana and Mobula thurstoni consisted mainly of euphausiids. Dietary niche breadth indicated a pelagic feeding behaviour of a specialist and a trophic level of a secondary predator for both M. mobular and M. munkiana. In contrast, Myliobatis chilensis and Myliobatis peruvianus consumed mostly gastropods and crustaceans. Dietary niche breadth indicated a feeding behaviour of a benthic specialist and a trophic level of a secondary predator for Myliobatis chilensis.

The morphometric relationships of the siphon clam Panopea globosa from Sinaloa, Mexico, were analyzed from February 2014 to April 2015. A total of 370 specimens were collected, measured (shell length, width, and height) and weighed (body weight, tissue weight, and shell weight). The coefficient of determination indicated variation in the fitting of morphometric variables among measured traits. The type of relative growth for all morphometric relationships was negative allometry. This is the first report on morphometric relationships of P. globosa from Sinaloa, Mexico.

Three species of Carangidae family were caught incidentally during collection of cannonball jellyfish (Stomolophus meleagris) in Bahía de La Paz, Gulf of California, Mexico. All fish were measured, preserved and identified as post flexion larvae and early juvenile of Chloroscombrus orqueta, Hemicaranx leucurus and Caranx caballus. C. orqueta stood out in frequency and abundance. H. leucurus were found only in autumn, while the others were present in different seasons. This is the first time recording H. leucurus and C. caballus associating with cannonball jellyfish. Further studies must evaluate this association as all fish caught were at vulnerable stages, and must be considered in jellyfish fishery management.

Ameghinomya antiqua is one of the most exploited bivalves in Chile, however, the limited information available on its reproductive biology does not allow proper fishery management decisions to be made. The presence of sexual dimorphism and the sex ratios for this species were detected by observation of gonads extracted from specimens collected from Carelmapu and Quellón, southern Chile. One group of specimens showed milky-white gonads with oocytes (females) while the other exhibited orange gonads with spermatocytes (males). The sex ratio obtained in Carelmapu was 1:1.1, with 48.5% males and 51.5% females; in Quellón, the sex ratio was 1:1.01, with 49.77% males and 50.23% females. We found that dimorphism can be assessed by rapid visual observation of the gonads. Our study proposes an easier and faster way of identifying gender in Ameghinomya antiqua, allowing proper monitoring.

Dusky dolphin Lagenorhynchus obscurus is distributed primarily in cool coastal waters at several continental margins and island borders in the Southern Hemisphere. Off Peru, the northernmost record of this species has been in front of the coast of Salaverry (ca., 6°S). In this paper, we report for the first-time a pod of dusky dolphin at the coast of Los Órganos (4°9.517’S; 81°11.958’W) northern Peru, thus extending the potential distributional range ca., 350 km towards the equator. A group of between 10 to 20 adult individuals was sighted on 17 October 2017, during a whale-watching excursion. Digital photographs and film allowed us to confirm the species based on body morphology and coloration. The sighted group was moving around the area without heading to a given direction. This record constitutes the northernmost record of dusky dolphin in Peru and arguably in the Southern Hemisphere.

The Southern elephant seal (SES) is a marine species that can be found at sea throughout the Southern Ocean on most sub-Antarctic islands. An unusual record of a solitary Southern elephant seal (Mirounga leonina) in freshwater habitat is reported. The seal was found 16 km upstream from the mouth of the Toltén River, in southern Chile (39°9’S; 73°10’W). The individual was classified as a sub-adult male approximately 3 m in length. Potential causes for the unusual presence of the seal in a river include feeding on native estuarine fishes and non-native Chinook salmon or resting. Long lasting resting (5 days) in the Toltén River by the seal may indicate suitable habitat and/or lack of disturbance.

Records on the diversity of algae serve as a foundation for establishing management and environmental protection programs, as well as for determining new commercial uses of algae. With this context in mind, the goal of the present study was to determine the richness, coverage, and composition of the macroalgae assemblage in the intertidal zone of Maitencillo, Valparaíso, Chile over the course of 3 years (2013-2015). A total of 29 species were recorded from three phyla - 23 Rhodophyta; 3 Ochrophyta, of the Phaeophyceae class; and 3 Chlorophyta. Species richness presented high spatial and temporal variations, with these variations most significantly explained by intertidal zone (61%) and the seasons (31%). The highest levels of specific richness were recorded in the mid and lower intertidal zones (14 species) in spring, as well as in the lower intertidal zone (14 species) during summer. The lowest values of specific richness were recorded for the mid intertidal zone (2 species) during fall. The distinct levels of the intertidal zone also notably impacted algae assemblage, explaining 53% of variation while the seasons explained 18% of variation. The greatest coverage was recorded in the mid intertidal zone during spring, with a predominance of Mazzaella laminarioides and Ulva spp. complex. In turn, the lowest coverage was found in fall, linked with processes of sand accretion. In rocky walls, the Pyropia complex dominated. Results indicate a marked pattern of vertical and seasonal distribution in the macroalgae assemblage, as well as notably high presence of Rhodophyta species. This benthic flora description serves to update information on the diversity of representative algal species from Valparaíso Region of Chile.   

Growth of microalgae Chlorella vulgaris and its efficiency in dissolved nutrients removal from effluent generated by yellowtail amberjack hatchery production were studied under laboratory scale conditions. This research evaluated indoor and outdoor conditions during 8 days, using filtered and UV light disinfected effluent, inoculated with an initial concentration of 2.06·106 ± 4.16·103 cells mL-1 of Chlorella vulgaris. In the determination of the growth and removal of nutrients, 12 transparent cylindrical-conical ponds with a capacity of 50 L were used. Three ponds were used for each experimental condition, indoor (3) and outdoor (3), with effluent water from the dorado culture, the remaining six ponds were controls using 1μm filtered seawater, disinfected and enriched with general culture medium F/2, in indoor (3) and outdoor (3), respectively. The result of growth under indoor condition reached a maximum value of 4.17·106   ± 7.57·105 cells mL-1 after 6 days. Similar growth was achieved in control tanks 4.75·106  ±  2.29·105 cells mL-1, whereas in outdoor experimental condition the maximum growth obtained was 2.81·106 ± 2.69·105 cells mL-1 reached on day 2, compared with controls that showed a maximum growth of 1.83·107 ± 2.29·105 cells mL-1. The best nutrient removal results recorded as nitrite removal were values of 91.67 and 88.41% (indoor and outdoor conditions, respectively). Nitrate removed reach a 57.47% (indoor) and 29.31% (outdoor) and a similar ammonia removal of 42.22% for both experimental conditions. Finally, high phosphate removal of 65.78% (indoor) and 75.78% (outdoor) were observed. The results show that the use of the microalga Chlorella vulgaris for the absorption of nutrients and growth in wastewater is feasible, which opens up encouraging perspectives for its application in purification processes in the fish farming activity or another industry that generates effluents with these characteristics.

This study investigated the tolerance of first-feeding larvae of spotted sand bass Paralabrax maculatofasciatus and spotted rose snapper Lutjanus guttatus to acute hyperosmotic stress. P. maculatofasciatus and L. guttatus embryos were incubated in 48-well microplates at 23 and 28°C, respectively. The first-feeding larvae were exposed in triplicate to salinities of 35 to 95 g L-1 or 35 to 85 g L-1, and survival was monitored from 0.5-3.5 h or 0.5-53 h, for P. maculatofasciatus and L. guttatus, respectively. The results showed that mortality increased differently among treatments from the first exposure time in each species. Extreme salinities were lethal in 30 min. Salinities close to the control were sub lethal. At intermediate salinities, mortality was fitted to a potential or linear model. For P. maculatofasciatus, the LC50 values obtained between 0.5 and 3.5 h were 73.4 to 65.4 g L-1. For L. guttatus the LC50 values obtained between 2 and 5 h were 57.3 to 54.5 g L-1. Comparison of LC50 between species showed that P. maculatofasciatus larvae had a higher tolerance to hyperosmotic stress. Based on the results for each species, it is recommended to expose to 70 g L-1 for 1 h for P. maculatofasciatus and 57 g L-1 for 2 h for L. guttatus when conducting hyperosmotic stress tests. This stress test is objective, simple, and can be used in both studies on broodstock nutrition and management and in hatcheries as a quality control method.