Parschisturella Andres 1983

Parschisturella Andres, 1983

(Fig. 29)

Parschisturella Andres, 1983: 212.— Barnard & Karaman, 1991: 517.

Type species. Parschisturella simplex Andres, 1983, original designation.

Included species. Parschisturella includes five species: P. carinata (Schellenberg, 1926b); P. martrudan sp. nov.; P. medora sp. nov.; P. pilot sp. nov.; P. simplex Andres, 1983.

Diagnostic description. Antenna 1 peduncle article 1 without anterodistal lobe; accessory flagellum without cap covering callynophore. Antenna 2 with brush setae. Labrum epistome and upper lip separate; upper lip strongly produced and apically acute. Mandible molar a reduced column, proximally setose, distally triturating or setose with distal triturating surface . Maxilla 1 outer plate a well developed 7/4 crown. Maxilla 2 inner plate slightly to significantly shorter than outer plate. Gnathopod 1 simple, parachelate or weakly subchelate; coxa 1 large, about as long as coxa 2, subrectangular with straight anterior margin; ischium short (length less than 2 × breadth); carpus long (length 2 to 4 × breadth); propodus margins tapering distally. Uropod 2 inner ramus constricted (weakly) or not. Telson deeply to moderately cleft.

Remarks. Six uristid genera (Eclecticus, Galathella, Ichnopus, Nagada, Paralibrotus and Parschisturella, have simple first gnathopods. Parschisturella does not appear to be particularly similar to any of these genera. All have four to five generic level differences from Parschisturella.

In Parschisturella gnathopod 1 varies from simple to weakly subchelate to parachelate and the telson varies from moderatly to deeply cleft. All species have a spine on the posterior margin of the gnathopod 1 dactylus. Parschisturella appears to be most smilar to the Australian endemic genus Des. The main differences between Parschisturella and Des are the accessory flagellum cap (absent or partially developed in Parschisturella, large and fully-developed in Des) and the labium (upper lip apically produced in Parschisturella and not produced in Des).

Until now Parschisturella has been considered an Antarctic endemic, but it is well represented in the temperate Australian fauna by at least three species.

Distribution. Antarctica and Australia.

Key to Parschisturella species

1. Gnathopod 1 parachelate....................................................................... P. carinata - Gnathopod 1 weakly subchelate......................................................................... 2 - Gnathopod 1 simple.................................................................................. 3 2. Epimeron 3 posteroventral corner forming a weak spine.............................................. P. medora - Epimeron 3 posteroventral corner acutely produced with a tiny notch....................................... P. pilot 3. Urosomite 1 evenly rounded. Telson with 2 apical robust setae per lobe................................ P. martrudan - Urosomite 1 dorsally straight. Telson with 4–5 apical robust setae per lobe................................ P. simplex