Hippoidea

Emerita analogs

The Hippo Idea are a globally widespread superfamily of funds cancers. Include for instance mole crabs and sand crabs, for a grave lifestyle in the marine littoral, is typical.

Features

The carapace of Hippo Idea is ovoid to nearly rectangular. It is coated with clear, mostly transverse depressions, which may be provided in Blepharipodidae and Albuneidae with bristles. The Antennulen (the first pair of antennas ) can be prolonged deep grave taxa to form a breathing tunnel. The eyes of Hippo Idea are variable. It is sufficient to form the handles, where the cornea is seated, many of, handle shaped to be comparatively short, and plate-shaped. The mouthparts are adapted either to the Aasfressen or filtering plankton and detritus. The gills are on an axis ( trichobranchiate ) or are paired leaf-shaped ( phyllobranchiate ). The first walking legs may have so-called Subchela or be completely without shearing at the Hippidae. The walking legs two to four pairs have a flat Dactyl, which can be dug in sandy substrates. Swimming legs are absent in males, or are reduced in some Albuneidae. The telson is always beaten by the abdomen, uropods do not form a tail fan.

Hippo Idea have lost the ability to walk and use their walking legs, relatively quick to burrow back into the sand. Some Hippo Idea can also swim backwards by paddling with the walking legs or with the uropods the so-called " tailflipping ". While digging, other types of decapods, but seems to deviate the backward ditch the Hippo Idea of those and thus to be a typical feature.

System

All phylogenetic studies indicate that the Hippo Idea are the basal taxon of funds cancers. The three families of Hippo Idea are themselves monophyletic, the Blepharipodidae described in 2002 are probably the sister taxon to the mole crabs and sand crabs. The families are distinguished by the shape of the gills ( trichobranchiat or phyllobranchiat ) and the absence or presence of a Subchela on the first walking legs.

The Hippo Idea consist of the following three families:

• Mole crabs ( Albuneidae Stimpson, 1858)
• Blepharipodidae Boyko, 2002
• Sand crabs ( Hippidae Latreille, 1825)