| Lophogastrida | |
|---|---|
| Gnathophausia zoea (Gnathophausiidae) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Crustacea |
| Class: | Malacostraca |
| Subclass: | Eumalacostraca |
| Superorder: | Peracarida |
| Order: | Lophogastrida G. O. Sars, 1870 |
| Families | |
|
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Lophogastrida is an order of malacostracan crustaceans in the superorder Peracarida. They are shrimp-like animals that mostly inhabit the relatively deep pelagic waters of the oceans throughout the world.[1]
Most lophogastridan species are 1–8 centimetres (0.4–3.1 in) long, but Gnathophausia ingens can be up to 35 cm (14 in), probably the largest pelagic crustacean in the world.[1] Some 56 extant species in total are currently known. They are classified into three families and nine genera.[2]
The external features of the Lophogastrida include stalked compound eyes, a carapace that covers the head and thoracic segments, and a muscular cylindrical abdomen. The carapace often extends beyond the head to form an elongated rostrum. As with other Peracarida, the Lophogastrida are separated from true shrimp in that they carry their developing embryos and young in a brood pouch, or marsupium, and they thus lack a separate planktonic larval stage.[3]
Previously, the Lophogastrida were classified as a suborder of a broader peracaridan order Mysidacea, together with the Mysida (and Stygiomysida), but that taxon is currently generally abandoned.[1][2][4][5] Features distinguishing the Lophogastrida from the Mysida include the absence of statocysts in their uropods, and the presence of well-developed biramous pleopods on the abdomen,[1] as well as molecular characters.[6]