Dictionary > Horseshoe crab

Horseshoe crab

Definition
noun, plural: horseshoe crabs
A crab-like marine chelicerate arthropod of the taxonomic family Limulidae
Supplement
The horseshoe crabs are marine arthropods. They belong to the family Limulidae and of the subphylum Chelicerata of Arthropoda. Horseshoe crabs are more closely related to the arachnids than to crustaceans. Thus, they are not truly crabs but chelicerates. The chelicerates are arthropods that are named for their feeding appendages called chelicerae. The chelicerae are specialized pair of appendages that appear before the mouth. The horseshoe crabs derive their name from their horseshoe shape carapace and their resemblance to crabs.
Horseshoe crabs have three major body regions: the head region or prosoma, the abdominal region or opisthosoma, and the tail region or telson. They have five pairs of appendages with a claw on each tip. Their mouth is in the center of their legs. Near the mouth is a pair of ventral eyes. Apart from these ventral eyes, they also have a pair of compound lateral eyes, a pair of median eyes, a pair of lateral eyes, and a single endoparietal eye.
The horseshoe crabs are regarded as living fossils. The species have existed for about 450 million years ago.1
Scientific classification:

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Subphylum: Chelicerata
  • Class: Merostomata
  • Order: Xiphosura
  • Family: Limulidae (Leach, 1819)2
  • Species: Limulus polyphemus (Atlantic horseshoe crab)

Carcinoscorpius rotundicauda (mangrove horseshoe crab)

Tachypleus gigas

Tachypleus tridentatus
Synonym(s):

  • Limulus
  • Molucca crab
  • horsefoot
  • king crab
  • saucepan

See also:

  • chelicerate
  • arthropod
  • Mentioned in:

    • Limulus lysate test

    Reference(s):

    1 Sadava, D., Heller, H. C., Hillis, D. M., and Berenbaum, M. (2009). Life: the Science of Biology (9th ed.). W. H. Freeman. p. 683

    2 Sekiguchi, K. (1988). Biology of Horseshoe Crabs. Science House.


    You will also like...

    Digestion and Absorption of Food
    Digestion and Absorption of Food

    The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and..

    Genetics and Evolution
    Genetics and Evolution

    Humans are diploid creatures. This means that for every chromosome in the body, there is another one to match it. Howeve..

    New Zealand Flora & Fauna
    Ecology & Biodiversity: New Zealand Flora & Fauna

    New Zealand is known for its unique biodiversity, caused by its remarkable geography and geologic history. Breaking away..

    Human Neurology
    Human Neurology

    Human Neurology deals essentially with the nervous system of humans. It also features the various theories put forward b..

    Cell Respiration
    Cell Respiration

    Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

    Ecosystem Succession
    Ecosystem Succession

    If the balance of nature is left untouched, landscapes can change dramatically over time. A previous ecosystem is supers..

    Related Articles...

    No related articles found

    See all Related Topics