Cryptic speciation in the giant Antarctic isopod Glyptonotus antarcticus (Isopoda: Valvifera: Chaetiliidae)

  title={Cryptic speciation in the giant Antarctic isopod Glyptonotus antarcticus (Isopoda: Valvifera: Chaetiliidae)},
  author={Christoph Held and Johann Wolfgang W{\"a}gele and Lehrstuhl f{\"u}r Spezielle Zoologie},
  journal={Scientia Marina},
SUMMARY: The genus Glyptonotus is most commonly regarded as monospecific, with Glyptonotus antarcticus Eights 1852 being its only constituent. Two more forms (G. acutus, G. antarcticus var. obtusus) that had been described based on morphological evidence have received little attention in the literature, though no formal attempt to evaluate their taxonomic status has been undertaken. In a survey of within-species genetic diversity, 23 specimens of the benthic Antarctic isopod Glyptonotus… 

Figures and Tables from this paper

Distinguishing cryptic species in Antarctic Asellota (Crustacea: Isopoda) - a preliminary study of mitochondrial DNA in Acanthaspidia drygalskii

The molecular data support the monophyly of all six species analysed, but there is only limited evidence for the interspecific relationships between the species.

Is the Scotia Sea a centre of Antarctic marine diversification? Some evidence of cryptic speciation in the circum-Antarctic bivalve Lissarca notorcadensis (Arcoidea: Philobryidae)

The authors' results provide initial evidence for reproductively isolated populations of L. notorcadensis and suggest the islands of the Scotia Sea appear to act as centres of speciation in the Southern Ocean.

Phylogeography of the high intertidal isopod Ligia pallasii Brandt, 1833 (Isopoda: Oniscidea) from the Aleutian Islands to Monterey Bay

The observed pattern of lower genetic divergence at higher latitudes suggests that processes (gene flow, selection, and drift) that lead to genetic divergence may vary as a function of latitude.

Crossing the polar front—Antarctic species discovery in the nudibranch genus Tritoniella (Gastropoda)

Tritoniella belli is the only valid species of a nudibranch genus endemic to the Southern Ocean. Recent exhaustive sampling and molecular analyses led to the discovery of several new lineages. A

Genetic diversity of Nymphon (Arthropoda: Pycnogonida: Nymphonidae) along the Antarctic Peninsula with a focus on Nymphon australe Hodgson 1902

The genetic diversity of several Nymphon species collected in the Antarctic Peninsular region is examined and Cytochrome c oxidase subunit I (COI) and 16S ribosomal gene data suggest a recent common history and/or recent gene-flow of N. australe populations across nearly 800 km of the Antarctic Peninsula.

Cryptic mitochondrial lineages in the widespread pycnogonid Colossendeis megalonyx Hoek, 1881 from Antarctic and Subantarctic waters

The data strongly support that nominal Colossendeis megalonyx consists of at least five cryptic and one pseudocryptic mitochondrial lineages, four of which appear to be geographically restricted, thus indicating high levels of gene flow or recent colonization in the Antarctic.

Population Genomics of Nymphon australe Hodgson, 1902 (Pycnogonida, Nymphonidae) in the Western Antarctic

It is proposed that the populations analyzed are divergent enough to constitute two different species from within this common Antarctic genus known for its phenotypic plasticity.



Marsupium morphology and brooding biology of the Antarctic giant isopod, Glyptonotus antarcticus Eights 1853 (Crustacea, Isopoda, Chaetiliidae)

It is suggested that, during the prolonged incubation of brood, adelphophagy contributes to the nourishment of the developing young, and assume that additional nutrition is provided by maternal secretion, which would partly explain marsupial conditions in G. antarcticus as an adaptation to slow development in an adverse environment.

Bryozoan colonization of the marine isopod Glyptonotus antarcticus at Signy Island, Antarctica

The diversity of epizoic bryozoans on the isopods is higher than on other host organisms from more stable environments, and this may be because of active selection by settling larvae.

Phylogeny and biogeography of serolid isopods (Crustacea, Isopoda, Serolidae) and the use of ribosomal expansion segments in molecular systematics.

  • C. Held
  • Biology
    Molecular phylogenetics and evolution
  • 2000
A V4 expansion segment is reported which exceeds the longest crustacean sequences known until now by more than 270 bp, indicating that all Antarctic species in this study form a monophyletic group which has probably derived from species with closest extant relatives in South America.

Molecular evidence for cryptic speciation within the widespread Antarctic crustacean Ceratoserolis trilobitoides (Crustacea, Isopoda)

The phylogenetic relationships of 14 species of the Antarctic amphipod families Epimeriidae and Iphimediidae were investigated using 553 bp of the gene for the mitochondrial cytochrome oxidase

Geographic and bathymetric patterns of mitochondrial 16S rRNA sequence divergence among deep-sea amphipods, Eurythenes gryllus

Analysis of DNA sequence diversity in E. gryllus indicates genetic homogeneity among sites within the same depth zone at the scale of ocean basins; and genetically divergent, cryptic taxa distributed at different depths, with the greatest diversity in the bathyal zone.


It is concluded that direct photostimulation of the intracerebral ocelli is likely and that functionally they could be analogous to the pineal organ of lower vertebrates.

Assimilation efficiency of the antarctic marine isopod Glyptonotus antarcticus

When fed shrimp every 2 days, the isopod Glyptonotus antarcticus Eights assimilated over 90% of the ingested food and results are discussed in relation to data for other isopods and marine invertebrates.

Temperature and embryonic development in polar marine invertebrates

Data from north Atlantic copepods indicate that it is suggested that the slow rates of embryonic development in many Antarctic marine invertebrates are the result of large egg size, and not the low temperature.

Resistance to freezing by Antarctic fauna: supercooling and osmoregulation.

Haemolymph oxygen transport and acid-base status in Glyptonotus antarcticus Eights

The blood-gas and acid-base status of Glyptonotus haemolymph may be a reflection of the low and stable temperatures experienced by this Antarctic crustacean.