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Enigmas de la ciencia: el calamar gigante
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... For example, the deep water trawl fi shery for orange roughy in New Zealand has yielded numerous Architeuthis specimens, because the (Guerra et al. 2004b, c). Architeuthis beaks and remains are found numerous times in the stomach contents of large marine mammals, sperm whales ( Fig. 2) (Whitehead 2003), sleeper sharks (Cherel and Duhamel 2004), and lancetfi sh and scabbardfi sh, for example (Roper and Young 1972), indicating they are an abundant and major component of the mesopelagic boundary ecosystems (Clarke 1962, 1980, 1997, Clark and MacLeod 1976, Guerra et al. 2006, Xavier 2006. While numerous specimens of Architeuthis have been recorded from Japanese waters, the fi rst specimen photographed alive was in 2005 by Kubodera and Mori (2005) followed by the significant recent event in 2012 of the fi lming of a live specimen in its natural habitat from a ROV and submersible (Widder 2013). ...
... , equatorial Atlantic (Nigmatullin 1976), the Bay of Biscay, Iberian Peninsula, and western Mediterranean Sea (Gonzales et al. 2002; Guerra et al. 2004a, b, c), Newfoundland shores and Grand Banks (Frost 1934, 1936, Aldrich and Brown 1967, Aldrich 1967, 1968, 1991, North Pacifi c (Nesis et al. 1985), and New Zealand (Forch 1998). Guerra et al (2006) and Winkleman et al. (2013) addressed the worldwide distribution and molecular population structure of Architeuthis specimens. A list of worldwide giant squid sightings and strandings from 1545-1996 is provided by Ellis (1998). ...
... Architeuthis records from the western North Atlantic, south and west of Newfoundland, and the Grand Banks have not been compiled and published since the extensive works of Verrill (1874Verrill ( , 1875a 1877, 1878, 1881b, 1882a, 1897a A brief summary of Architeuthis species, their distribution and biology, is provided by Roper and Jereb (2010). General publications of note on giant squid include those of Voss (1956Voss ( , 1959, Lane (1957), Toll and Hess (1981), Ellis (1994Ellis ( , 1998, Roper (1998Roper ( , 1999, Sweeney and Roper (2001), Soriano (2003), Kubodera and Mori (2005), Guerra et al. (2006), and Williams (2011), and the scholarly papers of Guerra (1992Guerra ( , 2003, Roper and Shea (2013), and Judkins et al. (2013). ...
This report provides information on 28 specimens of the giant squid, Architeuthis dux (Steenstrup 1857), discovered in the western North Atlantic Ocean between Newfoundland and the Gulf of Mexico. Some specimens have been reported in the press or popular literature, but others are recorded herein for the first time. Nominal architeuthid species are provided as well as tables listing repositories of types of nominal species, and repositories of non-type specimens from the study area. An extensive list of references of pertinent regional literature is provided, and recommendations for fixation and preservation are described.
... The giant squid, Architeuthis spp., is one of the largest invertebrates. Described primarily from remains in sperm whale stomachs, from carcasses of dead or moribund animals found floating on the ocean surface or washed up on beaches , and, rarely, from fresh specimens caught by deep-sea trawling activity [1], it was not until 2004 that a live specimen was observed in its natural habitat [2] and this year that the first video footage was published [3]. Because of their huge size and elusive nature, many myths and legendary sea monsters have been based on them, including the fabled sinker of ships, the Kraken. ...
... What is more certain is that, with the exception of the polar regions, Architeuthis are globally distributed [6,7]. Furthermore, they are probably voracious carnivores, preying upon fish, but also smaller cephalopods [1], including other giant squid [8] . Carbon and nitrogen isotope profiles obtained from analysing upper beaks suggest Architeuthis undergoes an ontogenetic diet shift early in life, abandoning smaller prey of relatively low trophic status in favour of larger prey of higher status. ...
... Isotope profiles also indicate that adult giant squid inhabit relatively small, welldefined and productive areas, where food resources have a constant carbon isotope composition [9]. It is also clear that juvenile giant squid are hunted by many other animals, including dolphins, fish and sea birds [1,10], and the adults are consumed in large quantities by whales, especially the sperm whale, Physeter macrocephalus [11]. As such it is likely (although unproved) that the giant squid population must be large, in order to sustain such levels of predation by whales. ...
Despite its charismatic appeal to both scientists and the general public, remarkably little is known about the giant squid Architeuthis, one of the largest of the invertebrates. Although specimens of Architeuthis are becoming more readily available owing to the advancement of deep-sea fishing techniques, considerable controversy exists with regard to topics as varied as their taxonomy, biology and even behaviour. In this study, we have characterized the mitochondrial genome (mitogenome) diversity of 43 Architeuthis samples collected from across the range of the species, in order to use genetic information to provide new and otherwise difficult to obtain insights into the life of this animal. The results show no detectable phylogenetic structure at the mitochondrial level and, furthermore, that the level of nucleotide diversity is exceptionally low. These observations are consistent with the hypotheses that there is only one global species of giant squid, Architeuthis dux (Steenstrup, 1857), and that it is highly vagile, possibly dispersing through both a drifting paralarval stage and migration of larger individuals. Demographic history analyses of the genetic data suggest that there has been a recent population expansion or selective sweep, which may explain the low level of genetic diversity.
... The giant squid, Architeuthis spp., is one of the largest invertebrates. Described primarily from remains in sperm whale stomachs, from carcasses of dead or moribund animals found floating on the ocean surface or washed up on beaches and, rarely, from fresh specimens caught by deep-sea trawling activity [1], it was not until 2004 that a live specimen was observed in its natural habitat [2] and this year that the first video footage was published [3]. Because of their huge size and elusive nature, many myths and legendary sea monsters have & 2013 The Author(s) Published by the Royal Society. ...
... What is more certain is that, with the exception of the polar regions, Architeuthis are globally distributed [6,7] . Furthermore, they are likely voracious carnivores , preying upon fish, but also smaller cephalopods [1], including other giant squid [8]. Carbon and nitrogen isotope profiles obtained from analysing upper beaks suggest Architeuthis undergoes an ontogenetic diet shift early in life, abandoning smaller prey of relatively low trophic status in favour of larger prey of higher status. ...
... Isotope profiles also indicate that adult giant squid inhabit relatively small, welldefined and productive areas, where food resources have a constant carbon isotope composition [9]. It is also clear that juvenile giant squid are hunted by many other animals, including dolphins, fish and sea birds [1,10], and the adults are consumed in large quantities by whales, especially the sperm whale, Physeter macrocephalus [11]. As such it is likely (although unproved) that the giant squid population must be large, in order to sustain such levels of predation by whales. ...
Despite its charismatic appeal to both scientists and the general public, remarkably little is known about the giant squid Architeuthis, one of the largest of the invertebrates. Although specimens of Architeuthis are becoming more readily available owing to the advancement of deep-sea fishing techniques, considerable controversy exists with regard to topics as varied as their taxonomy, biology and even behaviour. In this study, we have characterized the mitochondrial genome (mitogenome) diversity of 43 Architeuthis samples collected from across the range of the species, in order to use genetic information to provide new and otherwise difficult to obtain insights into the life of this animal. The results show no detectable phylogenetic structure at the mitochondrial level and, furthermore, that the level of nucleotide diversity is exceptionally low. These observations are consistent with the hypotheses that there is only one global species of giant squid, Architeuthis dux (Steenstrup, 1857), and that it is highly vagile, possibly dispersing through both a drifting paralarval stage and migration of larger individuals. Demographic history analyses of the genetic data suggest that there has been a recent population expansion or selective sweep, which may explain the low level of genetic diversity.
... Available information about the giant squid is fragmentary, based on dead or dying animals that have been washed ashore or been inadvertently captured in commercial trawl nets (Aldrich, 1991;Roeleveld & Lipinski 1991;Okiyama, 1993;Förch, 1998;González et al., 2002;Guerra et al., 2004;Kubodera, 2004). Most of A. dux specimens collected through occasional landing or stranding are in poor condition and their guts are often empty, with no morphologically recognisable content (Förch, 1998;Guerra et al., 2006). Available information describing the diet of A. dux from different locations reveals that fish and cephalopods are the main components, with the occasional presence of crustaceans (Pérez-Gándaras & Guerra, 1978;Förch, 1998;Lordan et al., 1998;Bolstad & O'Shea, 2004). ...
Architeuthis dux diet has been analysed according to information available from literature and from the analysis of gut contents of five females and two males from Mediterranean and Atlantic Iberian waters (20 specimens in total). This is the first time that A. dux diet from Atlantic and Mediterranean waters is described. Body weight of specimens ranged from 22.5 to 200 kg. In order to infer common patterns in giant squid diet according to its geographic distribution range, size and sex, available data on their diet composition structure were joined and examined with multivariate techniques. No significant differences in the trophic level on which A. dux prey on were found, considering size, sex and location. Thus, A. dux seems to play the same role in the trophic webs throughout the distribution range examined in this paper, which takes up a very wide geographic area. The trophic level estimated from the diet composition is 4.7. Obtained results show that this species preys mainly on pelagic fast swimmers and shoaling fishes and cephalopods as an opportunistic ambushing hunter.
... This is also where the large Architeuthis dux was captured, highlighting again the seemingly close relationship that exists between sperm whales and giant squid. This occurrence mirrors other studies (Guerra et al. 2006(Guerra et al. , 2011 where larger aggregations of predators and prey have been documented. The average southeastern species richness is lower, perhaps because of lower sampling effort. ...
Cephalopods of the northern Gulf of Mexico are widely distributed and provide an important food source for a variety of marine animals. Sperm whales are year-round residents in the northern Gulf of Mexico. Prey availability has been proposed as an explanation for this non-migratory whale population. To examine this explanation, a short pilot cruise was conducted during the summer of 2009 to test equipment and to obtain preliminary observations. Then the 3-month Sperm Whale Acoustic Prey Study (SWAPS) was conducted during the winter/spring of 2010 to sample the mid-water pelagic community for possible prey of sperm whales. it also compared sperm whale distribution wand prey composition across habitats of the northern gulf of Mexico. This paper focuses on the cephalopod diversity within the mid-water pelagic community and assesses the potential prey of the endangered sperm whales.
This report provides information on 28 specimens of the giant squid, Architeuthis dux (Steenstrup 1857), discovered in the western North Atlantic Ocean between Newfoundland and the Gulf of Mexico. Some specimens have been reported in the press or popular literature, but others are recorded herein for the first time. Nominal architeuthid species are provided as well as tables listing repositories of types of nominal species, and repositories of non-type specimens from the study area. An extensive list of references of pertinent regional literature is provided, and recommendations for fixation and preservation are described.
Guerra, Á., Rodríguez-Navarro, A. B., González, Á. F., Romanek, C. S., Álvarez-Lloret, P., and Pierce, G. J. 2010. Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks. – ICES Journal of Marine Science, 67: 1425–1431.
Carbon and nitrogen isotope profiles constructed from the upper beaks of four giant squid Architeuthis dux from the Bay of Biscay and Namibian waters provided a time-integrated record of their diet. Values of δ¹⁵N ranged from 5.5 to 13.4‰ and of δ¹³C from −14.4 to −17.8‰. Nitrogen isotope profiles differed significantly in shape among the four animals analysed, but δ¹⁵N increased along each profile, with lowest values around the rostral tip. The difference between the lowest and the highest δ¹⁵N values was ∼5.8‰, slightly less than a two-level difference between the trophic position of small and large A. dux. The increase in δ¹³C values was not as pronounced as for the δ¹⁵N profiles, but the changes suggest an ontogenetic shift in diet early in life from smaller prey of relatively low trophic status to larger prey of higher status. Fluctuations in δ¹³C values observed near the rostral tip may be associated with a greater intrinsic variability in the carbon isotope composition of relatively small prey, and/or transient migratory behaviour early in life. The relative stability of the δ¹³C profiles over the remainder of their lifespan is consistent with the hypothesis that adult giant squid inhabit relatively small, well-defined, and productive areas, where food resources have a constant carbon isotope composition.
The current public perception is that there is little reason for concern for the conservation of marine invertebrates, in part due to the scarcity of emblematic species to represent that diverse group. This paper shows that giant squid can be considered an emblematic species to represent concern for the conservation of marine invertebrate biodiversity because it satisfies all the requirements of an emblematic species. It shows that Architeuthis attracts public interest and attention and can serve as an indicator of oceanographic conditions and ocean climate change. It asserts that Architeuthis can represent concerns for vulnerable marine ecosystems associated with submarine canyons and that it belongs to a broad diverse phylogenetic group of organisms associated with these canyons, sharing common concerns with that group with respect to vulnerability and conservation. This study also advocates that the giant squid can serve as an indicator of effects of ecosystem stress resulting from anthropogenic effects including ocean acidification and warming. It is also shown to be vulnerable to such anthropogenic effects as fishing, acoustic seismic exploration and, possibly, pollutants.Highlights► Giant squids Architeuthis are emblematic. ► Giant squids as indicators of ocean climate change. ► Giant squids as indicators of anthropogenic impacts.
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