Topic
Ice worm
About: Ice worm is a research topic. Over the lifetime, 16 publications have been published within this topic receiving 228 citations. The topic is also known as: Mesenchytraeus.
Papers
TL;DR: The results raise the possibility that the glacier ice worm has exploited indigenous glacier bacteria, while several symbiotic bacterial lineages have maintained their association with the ice worm during the course of adaptive evolution to the permanently cold environment.
31 citations
TL;DR: It is reported that M. solifugus contains an elongated head pore at the tip of its prostomium, numerous sensory structures, and differentially oriented setae that curve abruptly at their distal end.
Abstract: Ice worms occupy a unique position in metazoan phylogeny in that they are the only known annelid that completes its life cycle in ice. The mechanism(s) associated with this adaptation are likely to occur at different levels, ranging from modification of their metabolism to changes in morphology. In this study, we examined specimens of Mesenchytraeus solifugus by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in an effort to identify morphologic structures that may aid in its glacial habitation. We report that M. solifugus contains an elongated head pore at the tip of its prostomium, numerous sensory structures, and differentially oriented setae that curve abruptly at their distal end. J. Morphol. 246:192–197, 2000. © 2000 Wiley-Liss, Inc.
29 citations
TL;DR: North American ice worms are the largest glacially-obligate metazoans, inhabiting coastal, temperate glaciers between southcentral Alaska and Oregon, and a broad survey throughout their geographic range is completed, indicating a gradual, northward expansion by active dispersal from the central St. Elias clade during the early-Pliocene.
23 citations
TL;DR: Cold sensitivity, together with southeast Alaska's geography and past climate, likely created the distribution gap, a hypothesis supported by their phylogeography.
Abstract: The North American glacier ice worm, Mesenchytraeus solifugus (Emery, 1898), is restricted to coastal glaciers in the American Pacific Northwest with a puzzling 400 km distribution gap along the Alaska-British Columbia border and several disjunct populations of northern clades in southern latitudes. We illustrate the role of minimum temperatures in ice worm behavior, abundance, and distribution. The study included 200 glaciers and 25 mitochondrial CO1 haplotypes from the species' 5 × 105 km2 geographic range. Minimum winter temperatures on the previous summer surface appear to determine: (1) the elevations ice worms occupy, (2) the glaciers that can support them, and (3) the mountain ranges they inhabit. Ice worms do not inhabit glaciers with over-winter temperatures below -7 °C on the previous summer surface. An annelid molecular clock in a Bayesian phylogeny suggests ice worms diverged from an aquatic ancestor 2.23 Ma, emerging as three clades 1.6–1.7 Ma. Cold sensitivity, together with southea...
22 citations
TL;DR: The previously unknown female and larva for the New Zealand glacier midge, Zealandochlus latipalpis Brundin, are described for the first time, and the pupa described more fully than previously.
Abstract: The previously unknown female and larva for the New Zealand glacier midge, Zealandochlus latipalpis Brundin are described for the first time, and the pupa described more fully than previously. Unlike the male, which is brachypterous, the female has large wings possessing traces of a vein between R1 and R4+5 uniquely for the subfamily Podonominae. The larvae, known locally as ice-worms, live in meltwater pools and ice caves of the Franz Joseph and Fox glaciers, New Zealand. Cladistic analysis of this highly autapomorphic species results in an unresolved trichotomy Zelandochlus + Parochlus + Podonomus, which is no advance on the suggestion made by Brundin (1966) concerning the relationships. Information is too scanty on many species of the putative related genera, but additional morphological features indicate that there may be a sister group relationship with part of Parochlus.
21 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 1 |
| 2018 | 2 |
| 2017 | 1 |
| 2016 | 1 |
| 2015 | 1 |