Guinotellus

Last updated

Guinotellus melvillensis is a species of crabs in the family Xanthidae, the only species in the genus Guinotellus. [1] It is a benthic crab with an ovate carapace within the subfamily Euxanthinae. [2]

Contents

G. melvillensis is a rare and unusual species of crab that has only been recorded in the Western Central Pacific, more specifically the Philippines. This species comes from the Xanthidae family [3] (which comprises the common mud crabs), [4] in the genus Guinotellus. G. melvillensis is the only crab of this family within the genus. [5]

They have been found in four locations all within the Philippines and at varying depths at each location, with some specimens being found in the intertidal as well as subtidal microhabitats.

Guinotellus melvillensis
Guinotellus melvillensis (MNHN-IU-2014-22644) 002.jpeg
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Subphylum:
Crustacea
Class:
Malacostraca
Order:
Decapoda
Infraorder:
Brachyura
Family:
Xanthidae
Genus:
Guinotellus

Serene, 1971
Species:
G. melvillensis
Binomial name
Guinotellus melvillensis
Serene, 1971

Description

The most distinctive feature of G. melvillensis is its oval-shaped carapace and shallow sub-hepatic cavities. Its carapace is broader than it is long, [6] with a ratio of roughly 1:1.2, and it lacks distinction between different regions. The sub-hepatic cavities (or cavities beneath the liver) are not unique to this genus, though they are distinctively shallow and are divided by a prominent crest, with crests along their sides as well. [2]

This crest is thought to work in conjunction with another unique feature, which is its modified claw. This claw has a modified upper arm portion, or merus, being significantly reduced. This reduced appendage is closely aligned with its first and longest leg, with the two being coapted. [2] The purpose of this modification is currently unknown.

Their size ranges from 2.0 to 200 mm, [7] with juveniles tending to have a smaller carapace width to length ratio. This species also has a distinctive gastrointestinal tract, with its dorsal lobe uniquely terminating in a hook shape; this is dissimilar to other Euxanthids, but is reminiscent of other crabs in its family, Xanthidae. It also lacks an external tooth. [2]

It is distinctive from other Euxanthines due to its unusually shaped carapace. Despite this, it is visually similar to other members of the subfamily Euxanthidae, such as Hypocolpus, Carpoporus, and Hepatoporus, with a notable resemblance to Hypocolpus due to the presence of subhepatic cavities. The two are distinguishable by the ratio of the carapace width and length, with it being 1:1.3+ in Hypocolpus and roughly 1:1.2 in G. melvillensis, as well as by this species’s distinctive gastrointestinal tract. [2]

There is notable sexual dimorphism, with females having a less broad carapace, smaller claws, and a distinctive vulva. [2]

Its coloration is undocumented, but it is assumed to be colorful like other xanthids. [8]

G. melvillensis has an anterolateral margin that does not meet the orbital margin but continues to meet antero-external region of the buccal frame. It also has a distinct subhepatic cavities present, with the chelipeds and walking legs that can be neatly fastened together against the carpus, which are ovoid and smooth. [2]

As there is limited research on this species the morphology can be described having the morphology being the most similar to species of hypocolpus. Which can be found in reef prairies of Thalassodendron [4]

They are especially similar in the structure of the basal antennal article, the anterior portion of the sternum, the form of the male abdomen, the cristate anterolateral margin of the carapace, and the way the fingers, palm, and carpus of the chelae follow the curve of the body surface against which they are fastened together [2]

Life History

G. melvillensis are commonly found with the benthic and tropical zones of the ocean. They are members of order Decapoda and are mostly gonochoric.

Habitat

This benthic species [9] has been documented in four locations within the Philippines thus far, including Balabac Island, Sibutu Island, Putic Island, and southern Luzon. [2] This area is known for being particularly dense in marine fauna, with many other species belonging to the infraorder Brachyura residing there. [10] Adult Xanthids are generally found in shallow water, and as such, the known G. melvillensis specimens were collected between depths of 2 to 73 meters. The areas in which they have been found contain coral reefs with large seaweed expanses, residing specifically within coral or on reef flats. This species is postulated to live in subtidal and intertidal zones. [2]

Mating

The reproductive behaviors of this species are not well documented, but based upon members of its order, Decapoda, they have separate male and female individuals that engage in courting behaviors. Copulation is only possible soon after the female molts, [11] at which point the crabs mate via indirect sperm transfer. [9]

Movement

The movement of these creatures is based on the walking legs that they possess. These walking legs densely setose at margins, less so on dorsal and ventral surfaces. They are relatively short, with their first walking legs being the longest.

Larval Stages

Although G. melvillensis has only be found in the Philippines, its larval stages can be compared to that of the family Xanthidae that it is a part of. The crab goes through 5 stages, four zoeal stages and a megalopa stage to end their larval life to enter into the adult stage. [12] During this larval period, they are notably pelagic.

Diet

The diet of G. melvillensis is somewhat unknown but from information taken from the family Xanthidae it can be suggested. Crustaceans are described as opportunistic omnivores as they utilise different types of food. However, most crustaceans are mainly omnivores with a tendency for herbivory in food habitats. For the P. vespertilio, a crustacean in the family Xanthidae similar to G. melvillensis, the most important food source was algae which was obtained by scrubbing the encrusted coralline substratum, with red algae (Rhodophyta) being the most common species to be consumed. The P. verspertilio also feeds on brittle stars, gastropods and bivalves, which displays the range of food sources that the family Xanthidae can consume. [13] It is possible that, like other Xanthids, it contains toxins as a result of its diet, and is thus poisonous. [14]

Classification History

The genus and species were first described by Raoul Serène (1909-1980) [15] in 1971, initially identified by a single juvenile male. [2] At least 13 additional organisms have been reidentified as G. melvillensis from museum collections in the National Museum of the Philippines and the Museum national d'Histoire naturelle. They were initially placed solely into the family Xanthidae in 1971, but were later revised to be added to the subfamily Euxanthidae in 1984. [2]

Bibliography

Related Research Articles

<span class="mw-page-title-main">Japanese spider crab</span> Species of crab

The Japanese spider crab is a species of marine crab and is the biggest one that lives in the waters around Japan. It has the largest known leg-span of any arthropod around 3.7 meters. The Japanese name for this species is taka-ashi-gani,, literally translating to “tall legs crab”. It goes through three main larval stages along with a prezoeal stage to grow to its great size.

<span class="mw-page-title-main">Xanthidae</span> Family of crabs

Xanthidae is a family of crabs known as gorilla crabs, mud crabs, pebble crabs or rubble crabs. Xanthid crabs are often brightly coloured and are highly poisonous, containing toxins which are not destroyed by cooking and for which no antidote is known. The toxins are similar to the tetrodotoxin and saxitoxin produced by puffer fish, and may be produced by bacteria in the genus Vibrio living in symbiosis with the crabs, mostly V. alginolyticus and V. parahaemolyticus.

<span class="mw-page-title-main">Raninidae</span> Family of crabs

Raninidae is a family of unusual crabs, sometimes known as "frog crabs", on account of their frog-like appearance. They are taken by most scientists to be quite primitive among the true crabs. They closely resemble the (unrelated) mole crabs, due to parallel evolution or convergent evolution. In both groups, the claws are modified into tools for digging, and the body is a rounded shape that is easy to bury in sand. Unlike most other true crabs, the abdomens of raninids are not curled under the cephalothorax.

<i>Tuerkayana hirtipes</i> Species of crab

Tuerkayana hirtipes is a species of terrestrial crab.

<span class="mw-page-title-main">Latreilliidae</span> Family of crabs

Latreilliidae is a small family of crabs. They are relatively small, long-legged crabs found on soft bottoms at depths of up 700 metres (2,300 ft) in mostly tropical and subtemperate waters around the world. Their carapace is very small and doesn’t cover the bases of their legs, which protrude from the cephalothorax in a spider-like manner. The family and its type genus are named after Pierre André Latreille. The oldest known fossils from the Latreillidae have been dated to the middle of the Cretaceous period. It comprises seven extant species.

<i>Pilumnus hirtellus</i> Species of crustacean

Pilumnus hirtellus, the bristly crab or hairy crab, is a species of European crab. It is less than 1 inch (25 mm) long and covered in hair. It lives in shallow water and feeds on carrion.

<i>Xantho poressa</i> Species of crab

Xantho poressa, the jaguar round crab, is a species of crab from the eastern Atlantic Ocean. It is one of four species in the genus Xantho.

<i>Ocypode gaudichaudii</i> Species of crab

Ocypode gaudichaudii, also known as the painted ghost crab or cart driver crab, is a species of crab found on Pacific beaches from El Salvador to Chile as well as on the Galápagos Islands. The species was first described by Henri Milne-Edwards and Hippolyte Lucas in 1843.

<i>Gelasimus vocans</i> Species of crab

Gelasimus vocans is a species of fiddler crab. It is found across the Indo-Pacific from the Red Sea, Zanzibar and Madagascar to Indonesia and the central Pacific Ocean. It lives in burrows up to 50 centimetres (20 in) deep. Several forms of G. vocans have been recognised, with their authors often granting them the taxonomic rank of full species or subspecies.

<i>Paractaea</i> Genus of crabs

Paractaea is a genus of crabs in the family Xanthidae, containing the following species:

<i>Polydectus</i> Genus of crabs

Polydectus cupulifer is a species of crab in the family Xanthidae, and the only species in the genus Polydectus. Together with the genus Lybia, it forms the subfamily Polydectinae. It is found in the Indo-Pacific, ranging from Madagascar and the Red Sea in the west to Japan, Hawaii and French Polynesia in the east. P. cupulifer is densely covered with setae (bristles), and frequently carries a sea anemone in each chela (claw).

<i>Euryxanthops</i> Genus of crabs

Euryxanthops is a genus of crabs in the family Xanthidae. It was originally established in 1983 by Garth & Kim to contain three species of deep-water crabs from Japan and the Philippines - Euryxanthops dorsiconvexus, Euryxanthops flexidentatus and Euryxanthops orientalis. Since then, several more species of this genus have been identified and described, and Euryxanthops currently contains:

Visayax is a genus of crabs in the family Xanthidae, containing the following species:

<i>Dyspanopeus sayi</i> Species of crab

Dyspanopeus sayi is a species of mud crab that is native to the Atlantic coast of North America. It has also become established outside its native range, living in Swansea Docks since 1960, the Mediterranean Sea since the 1970s, the North Sea since 2007 and the Black Sea since 2010. It can reach a carapace width of 20 mm (0.8 in), and has black tips to its unequal claws. It feeds on bivalves and barnacles, and is in turn eaten by predators including the Atlantic blue crab, Callinectes sapidus. Eggs are produced from spring to autumn, the offspring reach sexual maturity the following summer, and individuals can live for up to two years. The closest relative of D. sayi is D. texanus, which lives in the Gulf of Mexico; the two species differ in subtle features of the genitalia and the last pair of walking legs.

<i>Pyromaia tuberculata</i> Species of crab

Pyromaia tuberculata is a species of crab in the family Inachoididae.

<i>Dyspanopeus texanus</i> Species of crab

Dyspanopeus texanus is a species of crab known as the Texas mud crab.

<i>Haberma tingkok</i> Species of crustacean

The Micro Mangrove Crab (Haberma tingkok) is a species of micro-mangrove crab native to Hong Kong. It was first discovered by Stefano Cannicci from the University of Hong Kong and Peter Ng from the University of Singapore in the Ting Kok Mangrove forests in the northeast of Hong Kong and listed on the World Register of Marine Species (WoRMS) in April 2017. It was the third species placed in the genus Haberma, which was discovered in 2002.

<i>Latreillia elegans</i> Species of crustacean

Latreillia elegans is a species of crab belonging to the family Latreilliidae. This family of crabs is identified by their appearance as small, long-legged crabs. The species belongs to the genus Latreillia which has only five identified species: L. elegans, L. metanesa, L. williamsi, L.valida, and L. pennifera. It was previously thought that L.elegans and L.mannengi were two separate species, but it has since been revealed that the two species are synonymous. All the thought to be differences between L.elegans and L.mannengi were in actuality overlaps. The L. mannengi is simply referring to the close relative to the species of L. elegans found in the western Atlantic.

Parveen F. Absar is a wildlife biologist from India. In 2017, she was credited with the discovery of a species of freshwater crab called Teretamon absarum, of the genus Teretamon and species speleaum.

<i>Macrophthalmus pacificus</i> Species of sentinel crab

Macrophthalmus pacificus is a species of sentinel crab found widely across the Indo-West Pacific Ocean, including India, Japan, Malaysia, New Guinea, Solomon Islands, and northern Australia.

References

  1. 1 2 Peter K. L. Ng; Danièle Guinot & Peter J. F. Davie (2008). "Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world" (PDF). Raffles Bulletin of Zoology . 17: 1–286.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 Mendoza, Jose C. E.; Manuel-Santos, Marivene R.; Ng, Peter K. L. (2009). "Rediscovery of the rare euxanthine crab, Guinotellus melvillensis Serène, 1971 (Decapoda, Brachyura, Xanthidae) in the Philippines". Crustaceana. 82 (1): 39–51. doi:10.1163/156854008X363687. ISSN   0011-216X. JSTOR   27743252.
  3. 1 2 "WoRMS - World Register of Marine Species - Guinotellus melvillensis Serène, 1971". www.marinespecies.org. Retrieved 2022-04-25.
  4. 1 2 3 Vannini, Marco (1982). "Notes On Somalian Species of the Genus Hypocolpus (Decapoda, Brachyura, Xanthidae) With the Description of a New Species1)". Crustaceana. 42 (1–2): 101–105. doi:10.1163/156854082x00740. ISSN   0011-216X.
  5. 1 2 "Crab Database · Crabs · Species Guinotellus melvillensis". www.crabdatabase.info. Retrieved 2022-04-25.
  6. ↑ Serène, Raoul. "OBSERVATIONS PRÉLIMINAIRES SUR DES BRACHYOURES NOUVEAUX OU MAL CONNUS DU SUD-EST ASIATIQUE". Bulletin du Muséum National d'Histoire Naturelle. 2: 905.
  7. ↑ "WoRMS - World Register of Marine Species - Guinotellus Serène, 1971". www.marinespecies.org. Retrieved 2022-04-25.
  8. ↑ "Xanthid crabs (Xanthidae) on the Shores of Singapore". www.wildsingapore.com. Retrieved 2022-04-25.
  9. 1 2 3 "Guinotellus melvillensis". www.sealifebase.ca. Retrieved 2022-04-25.
  10. ↑ Manuel-Santos, Marivene; Ng, Peter; Mendoza, Jose (2009). "Rediscovery of the Rare Euxanthine Crab, Guinotellus Melvillensis Serène, 1971 (Decapoda, Brachyura, Xanthidae) in the Philippines". Crustaceana. 82 (1): 39–51. doi:10.1163/156854008x363687. ISSN   0011-216X.
  11. ↑ Salmon, Michael (January 1983). "Courtship, mating and sexual selection in decapod crustaceans". Studies in Adaptation.
  12. 1 2 Tan, Leo W.H.; Lim, Shirley S.L. (1981). "Larval Development of the Hairy Crab, Pilumnus Vespertilio (Fabricius) (Brachyura, Xanthidae) in the Laboratory and Comparisons With Larvae of Pil Umnus Dasypodus Kingsley and Pilumnussa Yi Rathbun". Crustaceana. 41 (1): 71–88. doi:10.1163/156854081x00093. ISSN   0011-216X.
  13. 1 2 Kyomo, Joel (2002). "Timing and Synchronization of the Breeding Period in Pilumnus vespertilio (Crustacea: Pilumnidae) in Subtropical Okinawa, Japan". Pacific Science. 56 (3): 317–328. doi:10.1353/psc.2002.0025. hdl: 10125/2568 . ISSN   1534-6188. S2CID   40950779.
  14. ↑ "Xanthid crabs". December 2019.
  15. ↑ Serène, Raoul (1984). Crustacés décapodes brachyoures de l'Océan Indien Occidental et de la Mer Rouge : Xanthoidea: Xanthidae et Trapeziidae : Addendum: Carpiliidae et Menippidae. O.R.S.T.O.M. ISBN   2-7099-0701-1. OCLC   488100732.
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.