Rectarcturus Schultz, 1981

Poore, Gary C. B., 2013, Rectarcturidae Poore, 2001 rediagnosed with descriptions of new Australian genera and species (Isopoda: Valvifera), Memoirs of Museum Victoria 70, pp. 17-36 : 23

Rectarcturus Schultz, 1981

Rectarcturus Schultz, 1981: 67–68 . – Park and Wägele, 1995:

69–71.

Type species. Arcturus kophameli Ohlin, 1901 , by original designation.

Diagnosis. Head, pereonites and anterior pereonites with paired blade-like submedian and sublateral tubercles or carinae, smooth or barely secondarily ornamented. Antenna 2.5–3 times dorsal length of (head + pereonite 1); article 3 cuboid, as long as deep, without ventrolateral flange; article 4 cylindrical, more than twice as long as fused articles (1 + 2); article 5 cylindrical, 0.7 times length of article 4, 5 times as long as wide. Pereopod 2 propodus palm straight, smooth; (dactylus body + unguis) as long as or little shorter than propodus; unguis setiform, little shorter than dactylus body. Pereopod 3 similar to pereopod 2, unguis shorter. Male pleopod 1 exopod groove ending obliquely on truncate distolateral lobe, not extending beyond distomesial seta-bearing lamina. Male pleopod 1 endopod about as long as exopod length. Oostegites 5 absent.

Composition. Rectarcturus kophameli ( Ohlin, 1901) , R. tuberculatus Schultz, 1981 .

Distribution. Argentina.

Remarks. Rectarcturus comprises two Argentinian species differentiated from those in the three Australian genera. The genus is most similar to Tasmarcturus but lacks the strong secondary ornamentation of the principal pereonal tubercles, has a much longer article 4 on the antenna, has a straight palm on pereopod 1 (all other genera are denticulate), the dactylus and unguis of pereopod 2 are little if at all longer than the propodus (much longer in all other genera), its unguis is shorter than the dactylus body (as long as or longer in others), and oostegites 5 are absent.