Distribution, growth, diet and foraging behaviour of the yellow‐fin notothen <i>Patagonotothen guntheri </i>(Norman) on the Shag Rocks shelf (Southern Ocean)

Collins, Martin A.; Shreeve, Rachael S.; Fielding, Sophie; Thurston, Michael H.

doi:10.1111/j.1095-8649.2007.01711.x

Cited by 30 publications

(13 citation statements)

References 19 publications

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“…In other parts of the Southern Ocean, the diet of E. antarctica is reported to be more diverse, being dominated by copepods in both the Lazarev Sea (Pakhomov et al 1996) and near Macquarie Island (Gaskett et al 2001) and dominated by euphausiids in the South Shetland Islands (Pusch et al 2004). T. gaudichaudii clearly plays a key role in the northern Scotia Sea, where it is also an important prey of notothenid fish (Collins et al 2008b, Main et al 2009) and seabirds (Croxall et al 1997), particularly in krill-poor years. It is also a key species on the Patagonian shelf and in other subAntarctic areas (Bocher et al 2001).…”

Section: Discussionmentioning

confidence: 99%

Feeding ecology of myctophid fishes in the northern Scotia Sea

Shreeve¹,

Collins²,

Tarling³

et al. 2009

Mar. Ecol. Prog. Ser.

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The diets of 9 species of myctophid fishes, Electrona carlsbergi, E. antarctica, Gymnoscopelus fraseri, G. nicholsi, G. braueri, Protomyctophum bolini, P. choriodon, Krefftichthys anderssoni and Nannobrachium achirus, were investigated during austral autumn in the northern Scotia Sea. Based on the percent index of relative importance (%IRI), the data suggest dietary specialisation in some species, which may permit resource partitioning. Hierarchical agglomerative cluster analysis of Bray-Curtis similarity (60% threshold) separated the myctophid community into distinct feeding guilds. One group (G. braueri and E. antarctica) fed principally on Themisto gaudichaudii, another (P. choriodon and G. fraseri) primarily on copepods (Metridia spp. and Rhincalanus gigas), and a third group (G. nicholsi and P. bolini) consumed copepods and euphausids (mostly Metridia spp. and Euphausia frigida). The diets of E. carlsbergi and K. anderssoni differed from the other species, with E. carlsbergi being the only species that consumed salps. There was a general switch in diet from copepods to euphausiids and amphipods as the myctophid predator size increased. Dietary specialisation is likely the result of a combination of predator size, gape size, filtering capacity of the gill rakers and the vertical distribution of predators and prey. Antarctic krill were only consumed by the larger myctophids, which represented a numerically minor part of the myctophid community, supporting the concept that myctophids can provide a krill-independent link between secondary production and higher trophic levels. However, the northern Scotia Sea is dominated by adult krill, which are only suitable as prey for larger fish. In the northern Scotia Sea, myctophid predation had a very small impact on copepod production but a higher impact on macrozooplankton, with a best-estimate of 4% of the daily production of Themisto gaudichaudii and 6% of that of Euphausia superba being consumed.

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Section: Discussionmentioning

confidence: 99%

Feeding ecology of myctophid fishes in the northern Scotia Sea

Shreeve¹,

Collins²,

Tarling³

et al. 2009

Mar. Ecol. Prog. Ser.

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“…It is nested within the Antarctic notothenioid clade and represents the second-most species-rich genus of Notothenioidei with 15 recognized species to date (Eastman and Eakin available at https://people.ohio.edu/eastman/; version Dec. 15, 2016), only surpassed in taxonomic diversity by the Antarctic genus Pogonophryne with 24 species. All Patagonotothen species occur in marine waters around the southern part of South America (Patagonia), the only exception being P. guntheri , which has a trans-Antarctic Polar Front range extending from the southern Patagonian Shelf to the Shag Rocks Shelf [10, 11]. Morphological analyses indicate that P. guntheri is a derived species within the genus, suggesting that it dispersed southward secondarily [10, 12] and that, therefore, the initial Patagonotothen radiation most likely occurred in non-Antarctic waters.…”

Section: Introductionmentioning

confidence: 99%

Phylogenomics of an extra-Antarctic notothenioid radiation reveals a previously unrecognized lineage and diffuse species boundaries

et al. 2019

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BackgroundThe impressive adaptive radiation of notothenioid fishes in Antarctic waters is generally thought to have been facilitated by an evolutionary key innovation, antifreeze glycoproteins, permitting the rapid evolution of more than 120 species subsequent to the Antarctic glaciation. By way of contrast, the second-most species-rich notothenioid genus, Patagonotothen, which is nested within the Antarctic clade of Notothenioidei, is almost exclusively found in the non-Antarctic waters of Patagonia. While the drivers of the diversification of Patagonotothen are currently unknown, they are unlikely to be related to antifreeze glycoproteins, given that water temperatures in Patagonia are well above freezing point. Here we performed a phylogenetic analysis based on genome-wide single nucleotide polymorphisms (SNPs) derived from restriction site-associated DNA sequencing (RADseq) in a total of twelve Patagonotothen species.ResultsWe present a well-supported, time-calibrated phylogenetic hypothesis including closely and distantly related outgroups, confirming the monophyly of the genus Patagonotothen with an origin approximately 3 million years ago and the paraphyly of both the sister genus Lepidonotothen and the family Notothenidae. Our phylogenomic and population genetic analyses highlight a previously unrecognized linage and provide evidence for shared genetic variation between some closely related species. We also provide a mitochondrial phylogeny showing mitonuclear discordance.ConclusionsBased on a combination of phylogenomic and population genomic approaches, we provide evidence for the existence of a new, potentially cryptic, Patagonotothen species, and demonstrate that genetic boundaries between some closely related species are diffuse, likely due to recent introgression and/or incomplete linage sorting. The detected mitonuclear discordance highlights the limitations of relying on a single locus for species barcoding. In addition, our time-calibrated phylogenetic hypothesis shows that the early burst of diversification roughly coincides with the onset of the intensification of Quaternary glacial cycles and that the rate of species accumulation may have been stepwise rather than constant. Our phylogenetic framework not only advances our understanding of the origin of a high-latitude marine radiation, but also provides the basis for the study of the ecology and life history of the genus Patagonotothen, as well as for their conservation and commercial management.Electronic supplementary materialThe online version of this article (10.1186/s12862-019-1345-z) contains supplementary material, which is available to authorized users.

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“…Despite proximity to South Georgia the Shag Rocks fauna is highly distinct, with the most abundant fish species being the notothenid, Patagonotothen guntheri, which is not found at South Georgia (Collins et al 2008).…”

Section: Discussionmentioning

confidence: 99%

Biology and distribution of South Georgia icefish (Pseudochaenichthys georgianus) around South Georgia and Shag Rocks

et al. 2008

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Pseudochaenichthys georgianus is a member of the unique Channichthyidae family of fishes, which lack haemoglobin. The distribution, length-frequency and summer diet are described from 14 bottom trawl surveys undertaken in the summers between 1986 and 2006. Pseudochaenichthys georgianus (50 -590 mm TL) were caught throughout the South Georgia shelf from depths of 76 -370 m, but very few specimens (, 1%) were caught on the Shag Rocks shelf. Multiple cohorts were present during each survey and length-frequency analysis of these cohorts suggests that growth is fast during the first 3 -4 years. Stomach contents analysis (2005 & 2006) indicated that P. georgianus is a pelagic or semi pelagic predator, with the summer diet dominated by Antarctic krill (Euphausia superba). Fish (channichthyids and notothenids) were also taken, but were a relatively minor part of the diet.

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Distribution, growth, diet and foraging behaviour of the yellow‐fin notothen Patagonotothen guntheri (Norman) on the Shag Rocks shelf (Southern Ocean)

Cited by 30 publications

References 19 publications

Feeding ecology of myctophid fishes in the northern Scotia Sea

Feeding ecology of myctophid fishes in the northern Scotia Sea

Phylogenomics of an extra-Antarctic notothenioid radiation reveals a previously unrecognized lineage and diffuse species boundaries

Biology and distribution of South Georgia icefish (Pseudochaenichthys georgianus) around South Georgia and Shag Rocks

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