Mitochondrial genome diversity and population structure of the giant squid Architeuthis : genetics sheds new light on one of the most enigmatic marine species

Abstract

Rua do Porto 18, 9939 430 Sao Joao, Lajes do Pico, Açores, PortugalDespite 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.

Bucking the trend: genetic analysis reveals high diversity, large population size and low differentiation in a deep ocean cetacean

“…There are both fish and squid species that exhibit similar levels of connectivity across comparable spatial scales (e.g., orange roughy (Hoplostethus atlanticus), Varela et al, 2012; giant squid (Architeuthis spp. ), Winkelmann et al, 2013) and it is likely that there are aspects of these species' population biology that are common. Thompson et al (2013) suggests that, given stranding patterns, seasonal shifts in distribution associated with the calving season are likely in Gray's beaked whales, perhaps in relation to a dependency on inshore waters.…”

Extraordinary numbers of giant squid, Architeuthis dux, encountered in Japanese coastal waters of the Sea of Japan from January 2014 to March 2015

“…Recent genetic study on whole mitochondrial DNA of the giant squid (Winkelmann et al 2013) demonstrated that there was no detectable phylogenetic structure at the mitochondrial level among 43 samples obtained from oceans all over the world, and the level of nucleotide diversity was exceptionally low. These results strongly support the hypothesis that only one global species, A. dux, is valid.…”

Open Access and the Changing Landscape of Research Impact Indicators: New Roles for Repositories

“…Altmetrics are best used to gauge immediate interest and attention towards recently published work and to identify channels and geographical locations where mentions and reference occur. Thus, the recently published article Mitochondrial genome diversity and population structure of the giant squid Architeuthis: Genetics sheds new light on one of the most enigmatic marine species, which is available in bibliography-only format in the repository [42], has already generated remarkable attention across social and researcher-oriented platforms including science blogs, Facebook and Twitter (Figure 8). However, it will be advisable to wait at least a couple of years before confirming whether such interest in the short-run will have any influence on citation counts.…”