Tachypleus tridentatus

Last updated

Tachypleus tridentatus
Tachypleus tridentatus.jpg
Male
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Order: Xiphosura
Family: Limulidae
Genus: Tachypleus
Species:
T. tridentatus
Binomial name
Tachypleus tridentatus
(Leach, 1819) [2]

Tachypleus tridentatus, commonly known as the Chinese horseshoe crab, Japanese horseshoe crab, or tri-spine horseshoe crab, is a species of horseshoe crab found in Southeast and East Asia, with records from China, Indonesia, Japan, South Korea, Malaysia, the Philippines, Taiwan, and Vietnam. [1] [3] It is found in coastal marine and brackish waters, and tolerates colder temperatures than the other Asian horseshoe crabs ( Tachypleus gigas and Carcinoscorpius rotundicauda ), although juveniles still need water warmer than 22 °C (72 °F) to moult. [3]

Contents

Description

Naturalis Biodiversity Center - RMNH.ART.28 - Tachypleus tridentatus - Kawahara Keiga - 1823 - 1829 - Siebold Collection - pencil drawing - water colour.jpeg
Naturalis Biodiversity Center - RMNH.ART.29 - Tachypleus tridentatus - Kawahara Keiga - 1823 - 1829 - Siebold Collection - pencil drawing - water colour.jpeg
Underside of male (above) and female (below) drawn and painted by Kawahara Keiga, 1823-1829. Notice the long spines on the rear carapace (six on either side in male, three in female) and the shape of the first two pairs of walking legs (hook-like in male, scissor-like in female)

Horseshoe crabs are not crabs at all, but are most closely related to spiders and scorpions, and may even be arachnids themselves. [4] The cephalothorax is protected by this single large, horseshoe-shaped plate, and neither it nor the abdomen is visibly segmented. The tail bears a long spike, known as the telson. [5] Like other horseshoe crabs, the carapace of T. tridentatus consists of a larger frontal one (the prosoma) and a smaller, spine-edged rear one (the opisthosoma). There are six pairs of prosomal appendages/legs, consisting of a small frontal pair in front of the mouth and five larger walking/pushing legs on either side of the mouth. The book gills are located on the underside of the opisthosoma. [6] Both the common name tri-spine horseshoe crab and the scientific name tridentatus refer to the three small spiny processes on the rear part of the opisthosoma (one spine in the middle above the tail and one on either side), while other species only have a single spine (in the middle). [7]

The tri-spine horseshoe crab is the largest of the living horseshoe crab species. [8] Like the other species, females grow larger than males. The largest females of the tri-spine horseshoe crab can be as much as 79.5 cm (31.3 in) long, including their tail. [9] On average in Sabah, Malaysia, females are about 66.5 cm (26.2 in) long, including a tail that is about 34.5 cm (13.6 in), and their carapace (prosoma) is about 31 cm (12 in) wide. In comparison, the average for males is about 54 cm (21 in) long, including a tail that is about 28.5 cm (11.2 in), and their carapace is about 25.5 cm (10.0 in) wide. [9] There are significant geographic variations in the size, but this does not follow a clear north–south or east–west pattern. The largest are from the Kota Kinabalu region in Malaysia where the average carapace width is about 38 cm (15 in) and 28 cm (11 in) in females and males respectively. The smallest are from Zhoushan region in China where the average carapace width is about 24 cm (9.4 in) and 22 cm (8.7 in) in females and males respectively. Intermediate average sizes, ranging from 28 to 33 cm (11–13 in) in females and 23 to 27 cm (9.1–10.6 in) in males, have been reported from Imari in Japan, Xiamen in China, the Philippines, and Manado, Tarakan, Padang and Sibolga in Indonesia. [6] Females typically reach maturity at a carapace width of about 27.5–28 cm (10.8–11.0 in) and males at 22.5–24.5 cm (8.9–9.6 in). Females weigh 1.4–4 kg (3.1–8.8 lb) and males 0.6–1.7 kg (1.3–3.7 lb). [9] In addition to the difference in size, males' two front pairs of walking legs, prosomal appendages two and three, have hooks (they are scissor-like in females) and they have six (three in females) long spines on either side of the rear carapace. [7] Juveniles (both sexes) also have six long spines on either side, similar to adult males. [7] From the eggs hatch to adulthood takes 4 years and involves 15 instar phases (14 moults). [10]

Ecology

Mating pair, with the smaller male having grasped the larger female Tachypleus tridentatus Cat Ba.JPG
Mating pair, with the smaller male having grasped the larger female

Like other species of horseshoe crabs, T. tridentatus is an omnivore and feeds on molluscs, worms, other benthic invertebrates and algae. [5] Large batches of eggs are laid in holes dug in sandy beaches in special nursery areas off the coast. On hatching, the larvae remain in the nest over winter, feeding on the yolks of their eggs for several months, remaining in this nursery area during the next spring and summer. As juveniles they remain buried in the sediment during high tide, emerging at low tide to feed on the exposed surface. They have limited opportunities to disperse widely. Adults move offshore for the winter, hibernating buried in the seabed at depths of around 20 metres (66 ft), coming inshore again when the water warms up the following year. As a poikilotherm, this horseshoe crab is much affected by rising seawater temperatures, reacting by burying itself deeply in the sediment and sometimes going into diapause. [11]

Status

Female Tachypleus tridentatus-2.jpg
Female

The tri-spine horseshoe crab are at risk from over-fishing, pollution and the loss of their breeding grounds. Populations have declined for decades, and the species was granted protection in Japan in 1928. In China it has become less common and, from being once abundant in Taiwan, it is now seldom seen inshore there. As of 2019, the International Union for Conservation of Nature classifies the species as "Endangered" based on recent population and habitat declines. [1]

Related Research Articles

<span class="mw-page-title-main">Chelicerata</span> Subphylum of arthropods

The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda. Chelicerates include the sea spiders, horseshoe crabs, and arachnids, as well as a number of extinct lineages, such as the eurypterids and chasmataspidids.

<span class="mw-page-title-main">Atlantic horseshoe crab</span> Species of arthropod

The Atlantic horseshoe crab, also known as the American horseshoe crab, is a species of horseshoe crab, a kind of marine and brackish chelicerate arthropod. It is found in the Gulf of Mexico and along the Atlantic coast of North America. The main area of annual migration is Delaware Bay along the South Jersey Delaware Bayshore.

<span class="mw-page-title-main">Horseshoe crab</span> Order of arthropods

Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura. Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids such as spiders, ticks, and scorpions.

<span class="mw-page-title-main">Xiphosura</span> Order of marine chelicerates

Xiphosura is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs. They first appeared in the Hirnantian. Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera.

<span class="mw-page-title-main">Mangrove horseshoe crab</span> Species of arthropod

The mangrove horseshoe crab, also known as the round-tailed horseshoe crab, is a species of horseshoe crab, a chelicerate arthropod found in tropical marine and brackish waters of India, Bangladesh, and Southeast Asia. It may also occur in Sri Lanka, Myanmar and the Philippines, but confirmed records are lacking. It is the only species in the genus Carcinoscorpius.

<span class="mw-page-title-main">Chasmataspidida</span> Order of arthropods

Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid-Devonian, with possible evidence suggesting that they were also present during the late Cambrian. Chasmataspidids are most easily recognised by having an opisthosoma divided into a wide forepart (preabdomen) and a narrow hind part (postabdomen) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural group.

<i>Willwerathia</i> Genus of horseshoe crab relatives

Willwerathia is a genus of Devonian arthropod. It is sometimes classified as synziphosurine, a paraphyletic group of horseshoe crab-like fossil chelicerate arthropods, while some studies compare its morphology to an artiopod. Willwerathia known only by one species, Willwerathia laticeps, discovered in deposits of the Devonian period from the Klerf Formation, in the Rhenish Slate Mountains of Germany.

<i>Bembicosoma</i> Extinct genus of chelicerate

Bembicosoma is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Bembicosoma was regarded as part of the clade Planaterga. Fossils of the single and type species, B. pomphicus, have been discovered in deposits of the Silurian period in the Pentland Hills, Scotland. Bembicosoma had been tentatively assigned as an eurypterid before its synziphosurine affinities revealed.

<i>Bunodes</i> Genus of horseshoe crab relatives

Bunodes is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Bunodes was regarded as part of the clade Planaterga. Fossils of the single and type species, B. lunula, have been discovered in deposits of the Silurian period in Ludlow, England. Bunodes is the type genus of the family Bunodidae, the other genera of the same family being Limuloides.

<i>Legrandella</i> Extinct genus of chelicerate

Legrandella is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Legrandella was regarded as part of the clade Prosomapoda. Fossils of the single and type species, L. lombardii, have been discovered in deposits of the Devonian period in Cochabamba, Bolivia.

<i>Pasternakevia</i> Extinct genus of chelicerate

Pasternakevia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Pasternakevia was regarded as part of the clade Planaterga. Fossils of the single and type species, P. podolica, have been discovered in deposits of the Silurian period in Podolia, Ukraine.

<i>Pseudoniscus</i> Extinct genus of chelicerate

Pseudoniscus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Pseudoniscus was regarded as part of the clade Planaterga. Fossils of the genus have been discovered in deposits of the Silurian period in the United Kingdom, the United States and Estonia. Pseudoniscus is one of the two members of the family Pseudoniscidae, the other being Cyamocephalus.

<i>Weinbergina</i> Extinct genus of chelicerate

Weinbergina is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Fossils of the single and type species, W. opitzi, have been discovered in deposits of the Devonian period in the Hunsrück Slate, Germany.

<span class="mw-page-title-main">Synziphosurina</span> Group of arthropods

Synziphosurina is a paraphyletic group of chelicerate arthropods previously thought to be basal horseshoe crabs (Xiphosura). It was later identified as a grade composed of various basal euchelicerates, eventually excluded form the monophyletic Xiphosura sensu stricto and only regarded as horseshoe crabs under a broader sense. Synziphosurines survived at least since early Ordovician to early Carboniferous in ages, with most species are known from the in-between Silurian strata.

<i>Tachypleus gigas</i> Species of arthropod

Tachypleus gigas, commonly known as the Indo-Pacific horseshoe crab, Indonesian horseshoe crab, Indian horseshoe crab, or southern horseshoe crab, is one of the four extant (living) species of horseshoe crab. It is found in coastal water in South and Southeast Asia at depths to 40 m (130 ft).

<span class="mw-page-title-main">Planaterga</span> Clade of arthropods

Planaterga is a clade of prosomapod euchelicerates including several synziphosurid genera and the group Dekatriata. Planaterga is defined by the opisthosoma with tergites broadest at third or fourth and lacking enlarged axial nodes, carapace with reduced genal spines, as well as somite VII with reduced appendages and microtergite.

<i>Houia</i> Extinct genus of arthropods

Houia is an extinct genus of dekatriatan, a clade of chelicerate arthropods. Fossils of Houia have been discovered in deposits of the Early Devonian period in Guangxi and Yunnan, both in China. The genus contains two species: H. guangxiensis, from the Pragian to Emsian epoch of Guangxi; and H. yueya, the type species, from the Lochkovian epoch of Yunnan. The name of the genus is derived from the Chinese character 鲎 (hòu), meaning "horseshoe crab".

<i>Venustulus</i> Extinct genus of chelicerate from Wisconsin

Venustulus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Venustulus was regarded as part of the clade Prosomapoda. Fossils of the single and type species, V. waukeshaensis, have been discovered in deposits of the Silurian period in Wisconsin, in the United States. Venustulus is one of the few synziphosurine genera with fossil showing evidence of appendages, the other ones being Weinbergina, Anderella and Camanchia. Despite often being aligned close to horseshoe crabs, it has been found that Venustulus and its relatives form a group made up of various basal euchelicerate arthropods more distant to the xiphosurans.

<i>Camanchia</i> Extinct genus of chelicerate

Camanchia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Camanchia was regarded as part of the clade Prosomapoda. Fossils of the single and type species, C. grovensis, have been discovered in deposits of the Silurian period in Iowa, in the United States. Alongside Venustulus, Camanchia is one of the only Silurian synziphosurine with fossil showing evidence of appendages.

<i>Chasmataspis</i> Extinct genus of arthropods

Chasmataspis is a genus of chasmataspidid, a group of extinct aquatic chelicerate arthropods. It was found in the Early Ordovician deposits of Tennessee, United States.

References

  1. 1 2 3 Laurie, K., Chen, C.-P., Cheung, S.G., Do, V., Hsieh, H., John, A., Mohamad, F., Seino, S., Nishida, S., Shin, P. & Yang, M. 2019. Tachypleus tridentatus (errata version published in 2019). The IUCN Red List of Threatened Species 2019: e.T21309A149768986. https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T21309A149768986.en. Downloaded on 12 April 2021.
  2. ↑ Boxshall, Geoff (2015). "Tachypleus tridentatus (Leach, 1819)". WoRMS. World Register of Marine Species . Retrieved 2015-08-22.
  3. 1 2 Stine Vestbo; Matthias Obst; Francisco J. Quevedo Fernandez; Itsara Intanai; Peter Funch (2018). "Present and Potential Future Distributions of Asian Horseshoe Crabs Determine Areas for Conservation" (PDF). Frontiers in Marine Science. 5 (164): 1–16. doi: 10.3389/fmars.2018.00164 .
  4. ↑ Sharma, Prashant P.; Ballesteros, Jesús A. (2019). "A Critical Appraisal of the Placement of Xiphosura (Chelicerata) with Account of Known Sources of Phylogenetic Error". Systematic Biology. 68 (6): 896–917. doi: 10.1093/sysbio/syz011 . PMID   30917194.
  5. 1 2 Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology (7th ed.). Cengage Learning. pp. 555–559. ISBN   978-81-315-0104-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  6. 1 2 Koichi Sekiguchi; Carl N. Shuster, Jr (2009). "Limits on the Global Distribution of Horseshoe Crabs (Limulacea): Lessons Learned from Two Lifetimes of Observations: Asia and America". In Tanacredi, John T.; Botton, Mark L.; Smith, David (eds.). Biology and Conservation of Horseshoe Crabs . Springer. pp.  5–24. ISBN   978-0-387-89959-6.
  7. 1 2 3 "Identification guide". Horseshoe Crab monitoring site. Retrieved 26 June 2018.
  8. ↑ "About the Species". The Horseshoe Crab. Retrieved 26 June 2018.
  9. 1 2 3 Azwarfarid Manca; Faridah Mohamad; Amirrudin Ahmad; Muhd Fawwaz Afham Mohd Sofa; Noraznawati Ismail (2017). "Tri-spine horseshoe crab, Tachypleus tridentatus (L.) in Sabah, Malaysia: the adult body sizes and population estimate". Journal of Asia-Pacific Biodiversity. 10 (3): 355–361. doi: 10.1016/j.japb.2017.04.011 .
  10. ↑ Yan Chen; C. W. Lau; S. G. Cheung; C. H. Ke; Paul K. S. Shin (2010). "Enhanced growth of juvenile Tachypleus tridentatus (Chelicerata: Xiphosura) in the laboratory: a step towards population restocking for conservation of the species". Aquatic Biology. 11: 37–40. doi: 10.3354/ab00289 .
  11. ↑ Menghong Hu; Youji Wang; Yan Chen; Siu-Gin Cheung; Paul K. S. Shin; Qiongzhen Li (2009). "Summer distribution and abundance of juvenile Chinese horseshoe crabs Tachypleus tridentatus along an intertidal zone in southern China". Aquatic Biology. 7: 107–112. doi: 10.3354/ab00194 .
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.