scholarly journals Analyzing drivers of speciation in the Southern Ocean using the sea spider species complex Colossendeis megalonyx as a test case

Polar Biology ◽  
2020 ◽  
Vol 43 (4) ◽  
pp. 319-342 ◽  
Author(s):  
Jana S. Dömel ◽  
Lars Dietz ◽  
Till-Hendrik Macher ◽  
Andrey Rozenberg ◽  
Christoph Mayer ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Species Complex ◽  
Test Case ◽  
Spider Species ◽  
Sea Spider

scholarly journals Regional differentiation and extensive hybridization between mitochondrial clades of the Southern Ocean giant sea spider Colossendeis megalonyx

2015 ◽  
Vol 2 (7) ◽  
pp. 140424 ◽  
Author(s):  
Lars Dietz ◽  
Claudia P. Arango ◽  
Jana S. Dömel ◽  
Kenneth M. Halanych ◽  
Avril M. Harder ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Cryptic Species ◽  
Global Climate ◽  
Regional Differentiation ◽  
Internal Transcribed Spacer Region ◽  
Mitochondrial Coi ◽  
Sea Spider ◽  
Distribution Ranges ◽  
Multiple Species ◽  
The Antarctic

Assessing the enormous diversity of Southern Ocean benthic species and their evolutionary histories is a central task in the era of global climate change. Based on mitochondrial markers, it was recently suggested that the circumpolar giant sea spider Colossendeis megalonyx comprises a complex of at least six cryptic species with mostly small and non-overlapping distribution ranges. Here, we expand the sampling to include over 500 mitochondrial COI sequences of specimens from around the Antarctic. Using multiple species delimitation approaches, the number of distinct mitochondrial OTUs increased from six to 15–20 with our larger dataset. In contrast to earlier studies, many of these clades show almost circumpolar distributions. Additionally, analysis of the nuclear internal transcribed spacer region for a subset of these specimens showed incongruence between nuclear and mitochondrial results. These mito-nuclear discordances suggest that several of the divergent mitochondrial lineages can hybridize and should not be interpreted as cryptic species. Our results suggest survival of C. megalonyx during Pleistocene glaciations in multiple refugia, some of them probably located on the Antarctic shelf, and emphasize the importance of multi-gene datasets to detect the presence of cryptic species, rather than their inference based on mitochondrial data alone.

A new species of Anoplodactylus (Arthropoda: Pycnogonida) from the Great Barrier Reef and discussion on the A. tenuicorpus-complex

Zootaxa ◽  
2007 ◽  
Vol 1435 (1) ◽  
pp. 19
Author(s):  
CLAUDIA P. ARANGO ◽  
FRANZ KRAPP
Keyword(s):  
New Species ◽  
Coral Reefs ◽  
Great Barrier Reef ◽  
Species Complex ◽  
Distribution Patterns ◽  
Species Boundaries ◽  
Barrier Reef ◽  
West Pacific ◽  
Sea Spider ◽  
A New Species

A new species of sea spider is described from the Great Barrier Reef, Australia. Anoplodactylus perissoporus n.sp. is in a species complex of extremely slender and tenuous forms that have serrated heel spines and are known to inhabit Indo- West Pacific coral reefs. The new species is characterized by the multiple cement gland pores on femora of males. Otherwise the species is very similar to, and probably closely related to A. tenuicorpus. The species boundaries within the A. tenuicorpus complex are difficult to discern and are not clearly defined, especially for females. Other character sets seem necessary to indicate affinities and distribution patterns of the tenuicorpus complex.

scholarly journals Do magnetic fabrics of marine deposits preserve orbital forcing? A test case in the Southern Ocean, Antarctic Peninsula

Lithosphere ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 751-756
Author(s):  
David K. Rea ◽  
Theodore C. Moore ◽  
Noralynn Hassold ◽  
Ben van der Pluijm
Keyword(s):  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Test Case ◽  
Orbital Forcing ◽  
Marine Deposits ◽  
Magnetic Fabrics

scholarly journals Optimizing Mooring Placement to Constrain Southern Ocean Air–Sea Fluxes

2020 ◽  
Vol 37 (8) ◽  
pp. 1365-1385
Author(s):  
Yanzhou Wei ◽  
Sarah T. Gille ◽  
Matthew R. Mazloff ◽  
Veronica Tamsitt ◽  
Sebastiaan Swart ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Numerical Weather Prediction ◽  
High Frequency ◽  
Weather Prediction ◽  
Low Frequency ◽  
Heat Fluxes ◽  
Test Case ◽  
Numerical Weather ◽  
Ocean Observing

AbstractProposals from multiple nations to deploy air–sea flux moorings in the Southern Ocean have raised the question of how to optimize the placement of these moorings in order to maximize their utility, both as contributors to the network of observations assimilated in numerical weather prediction and also as a means to study a broad range of processes driving air–sea fluxes. This study, developed as a contribution to the Southern Ocean Observing System (SOOS), proposes criteria that can be used to determine mooring siting to obtain best estimates of net air–sea heat flux (Qnet). Flux moorings are envisioned as one component of a multiplatform observing system, providing valuable in situ point time series measurements to be used alongside satellite data and observations from autonomous platforms and ships. Assimilating models (e.g., numerical weather prediction and reanalysis products) then offer the ability to synthesize the observing system and map properties between observations. This paper develops a framework for designing mooring array configurations to maximize the independence and utility of observations. As a test case, within the meridional band from 35° to 65°S we select eight mooring sites optimized to explain the largest fraction of the total variance (and thus to ensure the least variance of residual components) in the area south of 20°S. Results yield different optimal mooring sites for low-frequency interannual heat fluxes compared with higher-frequency subseasonal fluxes. With eight moorings, we could explain a maximum of 24.6% of high-frequency Qnet variability or 44.7% of low-frequency Qnet variability.

Larval morphologies and potential developmental modes of eight sea spider species (Arthropoda: Pycnogonida) from the southern Oregon coast

2010 ◽  
Vol 91 (4) ◽  
pp. 845-855 ◽  
Author(s):  
Z.P. Burris
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Characteristics ◽  
Postembryonic Development ◽  
Oregon Coast ◽  
Spider Species ◽  
Sea Spider ◽  
Mode Of Development ◽  
First Time ◽  
Scanning Electron

Larvae of eight sea spiders from three families (Ammotheidae, Pycnogonidae and Phoxichilidiidae) are described for the first time. The external morphology of the first larval stage of each species is presented in detail using scanning electron microscopy photographs in order to determine the mode of postembryonic development. Three types of larval development are apparent in the species examined. The speciesAchelia gracilipes, Eurycyde spinosa, Pycnogonum rickettsiandPycnogonum stearnsi(families Ammotheidae and Pycnogonidae) have larval morphologies indicative of an ‘ectoparasitic’ development. Morphological characteristics ofAchelia simplissimaandAchelia chelata(family Ammotheidae) larvae suggest an ‘endoparasitic’ development, while larvae of the speciesAnoplodactylus viridintestinalis(family Phoxichilidiidae) have traits implying an ‘encysting’ postembryonic mode of development. Larvae of the speciesNymphopsis spinosissimahave unusual morphological characteristics that may be indicative of a new developmental mode.

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