The role of the predator Trophon geversianus in an intertidal population of Mytilus chilensis in a rocky shore of the Beagle Channel, Tierra del Fuego, Argentina

2016 ◽  
Vol 12 (10) ◽  
pp. 1053-1063 ◽  
Author(s):  
Jessica Curelovich ◽  
Gustavo A. Lovrich ◽  
Javier A. Calcagno
Keyword(s):  
Rocky Shore ◽  
Tierra Del Fuego ◽  
Beagle Channel ◽  
Intertidal Population

scholarly journals Reproductive biology and energetics of the brooding sea star Anasterias antarctica (Echinodermata: Asteroidea) in the Beagle Channel, Tierra del Fuego, Argentina

2017 ◽  
Vol 65 (1-1) ◽  
pp. 221 ◽  
Author(s):  
Analía F. Pérez ◽  
Cintia Fraysse ◽  
Claudia C. Boy ◽  
Lucia Epherra ◽  
Calcagno Javier
Keyword(s):  
Tierra Del Fuego ◽  
Sea Star ◽  
Reproductive Condition ◽  
Sea Stars ◽  
Pyloric Caeca ◽  
Beagle Channel ◽  
Brooding Period ◽  
Wet Weight ◽  
Sexually Mature

The brooding sea star Anasterias antarctica is distributed from the coast of Patagonia to the northern Peninsula of Antarctica. In the Beagle Channel, the females of A. antarctica brood their eggs for seven months and do not feed during this period. The endoparasite Dendrogaster argentinensis (Crustacea: Ascothoracica) causes castration in several species of Anasterias. We randomly collected four samplings of adults in May, August and October (brooding period) and January (non-brooding period). The gonad (GI) and pyloric caeca index (PCI) were calculated as organ wet weight (g) x 100/total wet weight (g). Each individual was sexed by microscopic examination of the gonads. Sex ratio, brooding females/non-brooding females and mature females/non-mature females ratios was 1:1. The male GI reached maximum values in January, when most individuals were sexually mature. The GI of non-brooding females reached its maximum during October when it was significantly higher than those from brooding females. The PCI was minimum in October, being lower in brooding females (August and October). During the non-brooding period, mature females had a significantly higher GI than non-mature females. The PCI did not vary neither between males, nor between mature and non mature females. By the end of the brooding period, non-brooding females showed a higher GI than the brooding females. This is explained by proliferation and increase of the oocytes size of non-brooding females. Mature females showed an incremented GI with presence of mature oocytes, while non-mature females exhibited more abundance of previtelogenic oocytes. Males showed synchronicity in reproductive condition. The females that have not brooded presented a process of active gametogenesis, reaching the summer with a high GI, therefore becoming mature females. Females that had brooded were probably lacking energy for new gonadal maturation. The pyloric caeca would be performing the role of a reserve organ in the brooding females, decreasing its size during the brooding period. Prevalence of D. argentinensis in A. antarctica was 11.06%. As this parasite was recorded in sea stars lacking gonads, these infected hosts could have been castrated. Rev. Biol. Trop. 65(Suppl. 1): S221-S232. Epub 2017 November 01. 

Is the ‘Environment’ Good to Eat or Good to Paint? Faunal Consumption and Avoidance among Hunter-Gatherer-Fishers in the Beagle Channel Region (Tierra del Fuego, South America)

2013 ◽  
Author(s):  
Dánae Fiore ◽  
Angélica Tivoli
Keyword(s):  
South America ◽  
Tierra Del Fuego ◽  
Human Environment ◽  
Beagle Channel ◽  
Archaeological Data ◽  
Hypothetical Scenario ◽  
Human Practices ◽  
Industrial Societies ◽  
Optimality Models ◽  
Channel Region

This chapter discusses some aspects of the multi-dimensional nature of human–environment relationships. It focuses on the interaction established between people and animals in the Beagle Channel region (Tierra del Fuego, South America; Figure 5.1) through an analysis of taxon selection or avoidance in two inter-related spheres: subsistence and ceremonial art. The selection or avoidance of a particular species can be related to environmental, economic, political, and ideological factors, and our aim is to point out which of these factors influenced the high exploitation of certain taxa and the low representation of others. We achieve this by comparing archaeological data with spatially and temporally contemporaneous ethnographic information about the representation of animal species in ceremonial body paintings. Thus, we seek to explain whether the selection of some species and the avoidance of others in the subsistence sphere was being reinforced by or forbidden according to symbolic values that stemmed from the ceremonial sphere. Such questions derive from a theoretical premise that dismisses the notion of absolute optimality in human practices. It proposes instead that people’s actions and decisions are not guided only by rational principles and cost-minimizing aims: they can also be non-rational and non-optimal, and yet can make a socio-economic system function and reproduce efficiently through time and space without collapse. We argue that archaeological techniques and data have much to contribute to an understanding of the complexity of human–environment relations—particularly the ability to critique the overly simplistic economic models that often feed into popular and bureaucratic approaches to human environments. During the last fifteen years, one of the most popular approaches to subsistence in prehistoric and non-industrial societies has been the application of optimality models (e.g. Broughton 1994; Grayson and Delpech 1998; Nagaoka 2002, among others). In principle, these models were conceived as methodological tools through which the researcher lays out a hypothetical scenario of how resources should be consumed if people were trying to minimize costs and maximize benefits towards reaching an optimal result.

scholarly journals The role of Southern Hemispheric Westerlies for Holocene hydroclimatic changes in the steppe of Tierra del Fuego (Argentina)

2020 ◽  
Author(s):  
Cecilia Laprida ◽  
María Julia Orgeira ◽  
Marilén Fernández ◽  
Rita Tófalo ◽  
Josefina Ramón Mercau ◽  
...  
Keyword(s):  
Tierra Del Fuego

scholarly journals Feeding ecology of the crab Munida subrugosa (Decapoda: Anomura: Galatheidae) in the Beagle Channel, Argentina

2004 ◽  
Vol 84 (2) ◽  
pp. 359-365 ◽  
Author(s):  
M. Carolina Romero ◽  
Gustavo A. Lovrich ◽  
Federico Tapella ◽  
Sven Thatje
Keyword(s):  
Organic Matter ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Superficial Layer ◽  
Tierra Del Fuego ◽  
Crab Species ◽  
Monthly Basis ◽  
Beagle Channel ◽  
Food Items ◽  
Autumn And Winter

Munida subrugosa is the most abundant galatheid crab species in the Beagle Channel (55°S 68°W) off Tierra del Fuego, Argentina. Samples of crabs and the epibenthic community were taken on a monthly basis at two different depth strata (<40 m and >70 m), by means of epibenthic trawling from 1998 to 1999. Stomach contents from 1582 crabs were analysed, out of which only 2% had empty stomachs. The quantity of food in the stomach contents was clearly seasonal and similar at both depths. The organic matter varied throughout the year and between both depths, being significantly higher in summer/spring than in autumn/winter. Munida subrugosa shows two different and simultaneous feeding habits: (1) as a predator M. subrugosa feeds on crustaceans, algae, and polychaetes; and (2) as a deposit feeder M. subrugosa consumes particulate organic matter and organisms associated with the superficial layer of the sediment. The composition of the diet of Munida subrugosa was similar for both years, and independent of depth, sex or season. Munida subrugosa selected crustaceans only in autumn and winter, whereas most food items were found according to their availability in the habitat.

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