For the country, see Libya.

Lybia is a genus comprising eight species of small marine crabs from the family Xanthidae.[4] Commonly known as boxer crabs and pom-pom crabs, these crabs are famous for their symbiosis with small aquatic invertebrates, particularly sea anemones, which they hold in their claws for defense.[5] The genus has a diverse distribution, ranging across the Indo-Pacific[6] and originating as early as the Middle Miocene.[1] 

Morphology

Lybia crabs are small, achieving a maximum size of 1-2 cm in adulthood.[5] Each Lybia chelae (claw) is equipped with a set of small hooks, which aid the crab in maintaining its grasp on the anemone.[7] These claws are decidedly specialized for carrying anemones, and this appears to be its only function to the crab; when anemones are absent, Lybia chelae have not been observed in use for burrowing, defence, or prey capture.[8] They are devoid of any of the stereotypical features commonly associated with crab chelae. They are delicate and have no recorded observations of sexual dimorphism.[9]

Distribution

Estimated distribution of documented Lybia sightings.

The eight current species within Lybia are distributed across varying regions of the Indo-Pacific, including Hawaii, Indonesia, Japan, Australia, and Africa.[6] They tend to reside in warm, shallow marine waters, often hidden beneath rocks or coral.[10] The specific range of each species of Lybia is dependent on the distribution of their specific anemone-symbiont.[9]

Taxonomy

Lybia was first classified as a genus by Henri Milne-Edwards in 1834, with Grapse tessellata (later changed to Lybia tessellata) as the type species.[4]

The number of species within Lybia may be contentious.[5] Previously, ten species were documented; two have moved genuses and others may not be adequately defined. The species Tunebia hatagumoana and Tunebia tutelenia, once part of Lybia, now form the genus Tunebia.[3][11] Additionally, it has been suggested that Lybia leptochelis and Lybia pugil may be synonyms due to their morphological similarities.[11] These ten species, with the addition of the teddy bear crab (Polydectus cupulifer) of another genus, form the subfamily Polydectinae.[5]

The genus Lybia currently contains eight documented species:
Species[3][4] Image Known Distribution[5][6][9]
Lybia australiensis (Ward, 1933) None available. Australia
Lybia caestifera (Alcock, 1898) None available. China, Indian Ocean, Indonesia, Pacific Ocean, Papua New Guinea
Lybia denticulata Nobili, 1906 Red Sea
Lybia edmondsoni Takeda & Miyake, 1970 Hawaii (endemic)[10]
Lybia leptochelis (Zehntner, 1894) Red Sea, Fiji, Indonesia, Indo-Pacific (broad oceanic range)
Lybia plumosa Barnard, 1947 None available. South Africa, Indo-Pacific (broad oceanic range)
Lybia pugil (Alcock, 1898) None available. Australia, Indo-Pacific (broad oceanic range)
Lybia tessellata (Latreille in Milbert, 1812) East Africa, Red Sea, Indonesia, Australia, Indo-Pacific (broad oceanic range)

Using mitochondrial genomics, it has been estimated that the anemone-holding habits of Lybia's subfamily Polydectinae likely evolved during the Eocene 43 million years ago.[5] However, a paleontology study examining the fauna assemblages in the Indo-West Pacific has estimated that the genus Lybia did not arise until much later during the early Middle Miocene 16-15 million years ago.[1]

References

  1. ^ a b c Karasawa, H. (1993). "Cenozoic decapod Crustacea from southwest Japan". Bulletin of the Mizunami Fossil Museum. 20: 1–92.
  2. ^ "Lybia H. Milne Edwards, 1834". Integrated Taxonomic Information System. Retrieved March 1, 2011.
  3. ^ a b c Ng, Peter K. L.; Guinot, Danièle; Davie, Peter J. F. (January 2008). "Systema Brachyurorum: Part I. An Annotated Checklist of Extant Brachyuran Crabs of the World". The Raffles Bulletin of Zoology. 17: 1–286. Retrieved 8 June 2011.
  4. ^ a b c Boyko, Christopher B, ed. (27 August 2022). "Lybia H. Milne Edwards, 1834". WoRMS. Retrieved 4 October 2024.
  5. ^ a b c d e f Gries, Lennart; Paule, Juraj; Sonnewald, Moritz; Nilsson, Maria A (2024-02-01). "Eocene origin of anemone-carrying behaviour in polydectine crabs (Brachyura: Xanthidae)". Zoological Journal of the Linnean Society. 200 (2): 352–359. doi:10.1093/zoolinnean/zlad075. ISSN 0024-4082.
  6. ^ a b c Registry-Migration.Gbif.Org (2023). "Lybia H.Milne Edwards, 1834". GBIF Backbone Taxonomy (Dataset). doi:10.15468/39omei. Retrieved 2025-02-24.
  7. ^ Schnytzer, Yisrael; Giman, Yaniv; Karplus, Ilan; Achituv, Yair (2017-01-31). "Boxer crabs induce asexual reproduction of their associated sea anemones by splitting and intraspecific theft". PeerJ. 5: e2954. doi:10.7717/peerj.2954. ISSN 2167-8359. PMID 28168117.
  8. ^ Schnytzer, Yisrael; Giman, Yaniv; Karplus, Ilan; Achituv, Yair (2013-10-01). "Bonsai anemones: Growth suppression of sea anemones by their associated kleptoparasitic boxer crab". Journal of Experimental Marine Biology and Ecology. 448: 265–270. Bibcode:2013JEMBE.448..265S. doi:10.1016/j.jembe.2013.07.011. ISSN 0022-0981.
  9. ^ a b c Schnytzer, Yisrael; Achituv, Yair; Fiedler, G. Curt; Karplus, Ilan (2022). "The Intimate Relationship Between Boxer Crabs and Sea Anemones: What is Known and What is Not". Oceanography and Marine Biology. 60: 495–532. doi:10.1201/9781003288602-10. ISBN 978-1-003-28860-2. Retrieved 11 March 2025.
  10. ^ a b Karplus; Fiedler, GC; Ramcharan, P (1998). "The Intraspecific Fighting Behavior of the Hawaiian Boxer Crab, Lybia edmondsoni - Fighting with Dangerous Weapons?". Symbiosis. 24 (3): 287–302. Retrieved 27 February 2025.
  11. ^ a b Mendoza, Jose Christopher E; NG, Peter K L (2011). "The Polydectinae Dana, 1851, of the Philippines, with description of a new genus for Lybia hatagumoana Sakai, 1961 (Crustacea: Decapoda: Brachyura: Xanthidae)". Zootaxa. 3052: 51–61. doi:10.11646/zootaxa.3052.1.2. Retrieved 3 March 2025.


Allikas: Https://en.wikipedia.org/wiki/Lybia
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