Cumacea (Crustacea; Peracarida)of the Antarctic shelf - diversity,biogeography, and phylogeny

• Main Author: Rehm, Peter
• Other Authors: Arntz, Wolf E., Thatje, Sven
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2007
• Subjects: Cumacea; Ross Sea; diversity; Weddell Sea; Victoria Land; 16s rDNA; macrozoobenthos; Peracarida; Phylogeny; cryptic species; cryptic speciation; circumantarctic species; 570; 570 Life sciences; biology; ddc:570; Antarctic; Southern Ocean; The Antarctic; Weddell; Antarc*; antarcticus; Antarktis*
• Online Access: https://media.suub.uni-bremen.de/handle/elib/2454; https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000109173

The crustacean order Cumacea belongs to the Peracarida and comprises anevolutionary old group with conservative morphology. Predominantly bound to softbottom habitats in benthic marine environments they show a cosmopolitan distribution.As other Peracarida they display brood protection; juvenile stages are carried in themarsupium. It is supposed that the marsupium plays a major role in the success of thisabundant and specious group of Crustacea.The Peracarida are a dominant group in Southern Ocean benthic communities.Quantitative investigations of the Ross Sea shelf fauna demonstrated that thePeracarida contribute 63% to abundance and 50% to biomass. Amphipods dominatedclearly, while different sample sites yielded high dominances by Cumacea, Isopoda,and Tanaidacea. The recorded number of peracarid species from the Ross Sea is lowerthan in other high-Antarctic regions. The present study could show, that cumaceandiversity with respect to species richness resembles that of the Weddell Sea or the EastAntarctic. Species number has now increased from 13 to 34 for the Ross Sea, whichhighlights the requirement for choosing the appropriate sampling gear, and continued'classical' taxonomical as well as biogeographical work. With the present study equaldistribution of cumacean species with an affinity to the Magellan region in all high-Antarctic regions could be demonstrated.A new species Leucon rossi (see front page) and the subspecies Diastylisenigmatica rossensis was described from the Ross Sea. Further species from the Ross Seashowed slight morphological differences to literature. In the context of the discussionabout cryptic speciation these differences might indicate that diversity of Antarcticcumaceans is likely much higher as currently known. In the present study geneticdifferences in the 16S rRNA gene of populations of Leucon antarcticus from the RossSea and the Weddell Sea make clear that these have genetically separated for anextended period of time. According to the analysis of 16S rRNA data, populations of ...