Carpilius Maculatus
editThe Carpilius maculatus, commonly referred to as the seven-eleven crab, spotted reef crab, dark-finger coral crab, and large spotted crab, is a species of the family Carpiliidae, which also includes C. convexus and C. corallinus.[1] It is the most prominent of the genus Carpilius, due to its ability to be easily identified by the presence of eleven bright red spots located on its cream-colored carapace.[2]The spots are placed in a 2-3-4 design, with two at the front of its carapace, three across the middle, and four located at its posterior end.[2] While there have reports of the C. maculatus as being poisonous, biochemical testing has revealed that they lack any paralytic shellfish toxins.[3]At an average carapace width of 152 mm, it is larger in size in regards to other xanthids.[1]The C. maculatus has a smooth carapace and general appearance, with the exception of four protruding spines located between its eyes.[2]These crabs are typically found on coral and rocky reef substrates generally in the Indo-West Pacific.[4]Yet, these crabs are also found outside of the Indo-West Pacific region, with findings of C. maculatus reported from Hawaii to Mozambique and South Africa.[1]The closely related Carpilius convexus is also generally found in the Indo-West Pacific region, whereas the Carpilius corallinus is located primarily in the central western Atlantic Ocean.[5]The C. maculatus is nocturnal in nature, actively scavenging at night along the ocean floor.[6]
Feeding
editThe nocturnal nature of the Carpilius maculatus leads it to hunt primarily at night, with its diet consisting mainly of marine snails.[7]Observations of feeding behavior revealed that Carpilius maculatus initially attack the legs or small claws of its prey, before utilizing its master claw in order to crush the shells of its prey.[7]The larger size of these master claws allows the C. maculatus to feed efficiently on bigger members of its prey species[7] In general, C. carpilius tends to avoid consuming smaller-sized prey (< 10 mm).[7]Proximal molars are located on these master claws that aid it in its shell- and spire-crushing behavior.[7]
Phylogenetic Relationships
editWhile scientists previously grouped the genus Carpilius with other crabs of the Xanthiae family, recent research on mitochondrial gene fragments of the Carpilius crabs has granted it its status as a separate monotypic genus within its distinct family, Carpiliidae.[1] Fossil records of crabs classified within the family Carpiliidae have linked it to the genera Palaeocarpilius, which was present during the middle to upper Eocene Epoch approximately 56 million years ago and found in what is now modern-day Europe, India, and Egypt.[8] The family Carpiliidae has also been associated with the Harpactoxanthopsis of Europe – a now extinct family located within the superfamily Carpilioidea.[1]This fossil record, however, is insufficient to establish a biological origination point for the group.[1] Mitogenome analysis of C. maculatus has also allowed scientists to place Carpilius maculatus within the Heterotremata species, a clade of freshwater crabs.[6]
- ^ a b c d e f Wetzer R, Martin JW, Trautwein SE. 2003. Phylogenetic relationships within the coral crab genus Carpilius (Brachyura, Xanthoidea, Carpiliidae) and of the Carpiliidae to other xanthoid crab families based on molecular sequence data. Mol Phylogenet Evol. 27:410–421.
- ^ a b c Raju B, Raheem P, Anil M, Saleela K. 2015. First report of Spotted reef crab off Vizhinjam coast. Mar Fish Inf S; Tech Extension S. 2015:23–24.
- ^ Raj U, Haq H, Oshima Y, Yasumoto T.1983. The occurrence of paralytic shellfish toxins in two species of xanthid crab from Suva barrier reef, Fiji Islands. Toxicon. 21(4):547-51
- ^ Zacharia P, Krishnakumar P, Dineshbabu A, Vijayakumaran K, Rohit P, Thomas S, Sasikumar G, Kaladharan P, Durgekar NR, Mohamed K. 2008. Species assemblage in the coral reef ecosystem of Netrani Island off Karnataka along the southwest coast of India. J Mar Biol Assoc India. 50:87–97.
- ^ Paul F. Clark, Peter K. L. Ng, Hitoshi Noho, Shigemitsu Shokita. 2005. The first-stage zoeas of Carpilius convexus (Forskal, 1775) and Carpilius maculatus (Linnaeus, 1758) (Crustacea:Decapoda: Brachyura: Xanthoidea: Carpiliidae): an example of heterochrony. Journal of Plankton Research, Vol. 27, 2. pp. 211-219.
- ^ a b Hongtao Liu, Mingqui Yang, Yugui He. 2019. Characterization of complete mitochondrial genome of seven-eleven crab Carpilius maculatus (Linnaeus, 1758). Mitochondrial DNA Part B, 4:2. DOI: 10.1080/23802359.2019.1679682
- ^ a b c d e Edith Zipser, Geerat J. Vermeij. 1978. Crushing behavior of tropical and temperate crabs. Journal of Experimental Marine Biology and Ecology, Vol. 31, 2. pp. 155-172.
- ^ Schweitzer, C.E., Feldmann, R.M., Tucker, A.B., Berglund, R.E., 2000. Eocene decapod crustaceans from Pulali Point, Washington. Ann. Carnegie Mus. 69, 23–67.