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Family: Alpheidae
Snapping Shrimp
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Bocas Species Database Habitat: This species will favor habitats such as sand-rubble bottoms, crevices of coral rocks, dead corals and seagrass. Distribution: So far, this species has been reported only from Panama and Honduras. However, it is thought that its range could extend in the Caribbean Sea to southern Florida. Natural History Notes: Alpheus paraformosus has two closely related species, which are the transisthmian sister species, A. panamensis and A. formosus. A. paraformosus differs from those species by two important morphological characters: the absence of balaeniceps setae on the fingers of the minor chela and the short adrostral furrows. Also, A. paraformosus is somehow smaller than the two other species and shows several differences in color pattern. A study conducted by Williams et al. (2001) looked at the phylogenetic relationships within the genus Alpheus, using the sequence data of two nuclear genes and a mitochondrial gene called cytochtome oxidase I. The phylogenetic analyses led to the discovery of three new lineages within the genus Alpheus. Those results suggested that specialized ecological conditions and different claw morphologies among the genus Alpheus would have evolved independently several times. It also raised questions about whether or not the genus Alpheus should be split into three or several genera. The authors suggested that those three lineages should at least receive the status of subgenus. A. paraformosus would be part of the Alpheus formosus species complex and would belong to Clade III. Depth: Present in the lower intertidal and shallow subtidal, to 5 m. Characteristics: Alpheus paraformosus has a body length of up to 22 mm. The carapace has a slightly compressed shape and does not show any hair. The rostrum (foremost extension of the carapace) is well developed and the dorsal side is more flat. On the side of the body, we can distinguish some setae, which are hair-like structures that help gathering phytoplankton. Then, we can distinguish the orbital hoods and some teeth present on the anterior margin. Due to the presence of furrows, the eyes are masked when you look at the shrimp from a dorsal, lateral or partly frontal view. The antenna, mouthpart and major and minor chela are typical for the Alpheus genus. The coloration pattern of A. paraformosus consists of a dark purple body with pale yellow mediodorsal bands extending from the anterior part to the cardiac notch. The yellow band then continues as a white band that will end at the sixth abdominal somite. The rostrum is yellow with some red on the margins and the carapace shows some white bands on the flanks. The walking legs are blue to purple and the antennas are gray-blue. The major chela (claw) has a pale orange patch at the tip and a brown-orange patch near the articulations. Finally, the tail fan, composed of the telson and the uropods, has some bluish patches. The eggs of the ovigerous females will be reddish orange. Notes: This species was named “paraformosus” to point out the great resemblance to the other Alpheus species, A. formosus (morphology and color pattern). |