Horseshoe Crab: the living fossil: Difference between revisions
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Present-day horseshoe crabs are all marine dwellers although forays into freshwater have been noted among long extinct groups. The mangrove horseshoe crab, at odds with the other three extant species, does inhabit brackish waters | Present-day horseshoe crabs are all marine dwellers although forays into freshwater have been noted among long extinct groups. The mangrove horseshoe crab, at odds with the other three extant species, does inhabit brackish waters | ||
[[Image: | [[Image:https://dfzljdn9uc3pi.cloudfront.net/2020/10431/1/fig-3-2x.jpg|thumb|200px|left|Figure 1. Front and back views of Limulus polyphemus showing general morphology[https://peerj.com/articles/10431/]] | ||
<br>At right is a sample image insertion. It works for any image uploaded anywhere to MicrobeWiki. The insertion code consists of: | <br>At right is a sample image insertion. It works for any image uploaded anywhere to MicrobeWiki. The insertion code consists of: | ||
Revision as of 16:44, 11 December 2024
Introduction
Select a topic about genetics or evolution in a specific organism or ecosystem.
Overall text length (all text sections) should be at least 1,000 words (before counting references), with at least 2 images.
The topic must include one section about microbes (bacteria, viruses, fungi, or protists). This is easy because all organisms and ecosystems have microbes.
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First emerging in the Late Ordovician period of the Paleozoic era (Rudkin DM, Young GA, Nowlan GS. The oldest horseshoe crab: a new xiphosurid from Late Ordovician Konservat‐Lagerstätten deposits, Manitoba, Canada. Palaeontology. 2008 Jan;51(1):1-9.), horseshoe crabs are some of the most ancestral species of animals still alive today. Marine chelicerates belonging to the order Xiphosura, only four extant species remain. While their resemblance to a horseshoe is difficult to contest, “crab” is a misnomer for the creatures considering they are not even crustaceans. They are, in fact, more closely related to arachnids, which include, among others, spiders and scorpions. Notwithstanding minor changes, the morphology of horseshoe crabs has remained virtually unchanged throughout its existence, rewarding them the epithet of “living fossils”.
The characteristic blue hemolymph, the equivalent of blood in invertebrates, of horseshoe crabs has been indispensable to human health since the 1970s, owing to their usage in TAL and LAL.
All horseshoe crabs share the same body plan: the cephalothorax or prosoma (head and chest fused together), the opisthosoma (the abdomen with the inclusion of the heart and respiratory organs, a distinctive feature of the chelicerates) and, the iconic feature of the horseshoe crab, the telson (the long tail-like spine jutting out from the abdomen). The prosoma is shrouded in a protective carapace bearing an uncanny resemblance to a horseshoe, giving the horseshoe crab its name. Unlike any other extant chelicerate, horseshoe crabs possess, among its ten eyes, two compound eyes that sit atop its carapace; they also have the largest rod and cone cells of any known animal.
Present-day horseshoe crabs are all marine dwellers although forays into freshwater have been noted among long extinct groups. The mangrove horseshoe crab, at odds with the other three extant species, does inhabit brackish waters
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Legend/credit: Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.
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Section 1 Genetics Phylogeny and Evolution
Section titles are optional.
Include some current research, with at least one image.
Call out each figure by number (Fig. 1).
Sample citations: [1]
[2]
A citation code consists of a hyperlinked reference within "ref" begin and end codes.
For multiple use of the same inline citation or footnote, you can use the named references feature, choosing a name to identify the inline citation, and typing [4]
Second citation of Ref 1: [1]
Here we cite April Murphy's paper on microbiomes of the Kokosing river. [5]
Section 2 Microbiome
Include some current research, with a second image.
Here we cite Murphy's microbiome research again.[5]
Conclusion
You may have a short concluding section.
Overall, cite at least 5 references under References section.
References
- ↑ 1.0 1.1 Hodgkin, J. and Partridge, F.A. "Caenorhabditis elegans meets microsporidia: the nematode killers from Paris." 2008. PLoS Biology 6:2634-2637.
- ↑ Bartlett et al.: Oncolytic viruses as therapeutic cancer vaccines. Molecular Cancer 2013 12:103.
- ↑ Lee G, Low RI, Amsterdam EA, Demaria AN, Huber PW, Mason DT. Hemodynamic effects of morphine and nalbuphine in acute myocardial infarction. Clinical Pharmacology & Therapeutics. 1981 May;29(5):576-81.
- ↑ 4.0 4.1 text of the citation
- ↑ 5.0 5.1 Murphy A, Barich D, Fennessy MS, Slonczewski JL. An Ohio State Scenic River Shows Elevated Antibiotic Resistance Genes, Including Acinetobacter Tetracycline and Macrolide Resistance, Downstream of Wastewater Treatment Plant Effluent. Microbiology Spectrum. 2021 Sep 1;9(2):e00941-21.
- ↑ 6.0 6.1 Lamsdell JC. The phylogeny and systematics of Xiphosura. PeerJ. 2020 Dec 4;8:e10431.
Edited by [Author Name], student of Joan Slonczewski for BIOL 116, 2024, Kenyon College.
