Ianiropsis Sars, 1897

Doti, Brenda Lía & Wilson, George D. F., 2010, The genera Carpias Richardson, Ianiropsis Sars and Janaira Moreira & Pires (Isopoda: Asellota: Janiridae) from Australia, with description of three new species, Zootaxa 2625, pp. 1-39 : 14-15

Ianiropsis Sars, 1897

Ianiropsis G.O. Sars, 1897: 102 .— Menzies, 1952: 134; 1962: 78; Kussakin, 1962: 40; 1988: 88; Wilson & Wägele, 1994: 702 –703.

Janiropsis . — Richardson, 1905: 454; Gurjanova, 1936: 44.

Type species. Janira breviremis Sars, 1883 , by subsequent designation.

Species included. I. alanmillari sp. nov., I. analoga Menzies, 1952 ; I. breviremis ( Sars, 1883) ; I. derjugini Gurjanova, 1933 ; I. epilittoralis Menzies, 1952 ; I. kincaidi Richardson, 1904 ; I. koreaensis Jang & Kwon, 1990 ; I. kussakini Carvacho, 1982 ; I. longiantennata Thielemann, 1910 ; I. longipes Sivertsen & Holthuis, 1980 ; I. magnocula Menzies, 1952 ; I. minuta Menzies, 1952 ; I. montereyensis Menzies, 1952 ; I. neglecta ( Chilton, 1909) ; I. notoensis Nunomura, 1985 ; I. pallidocula Kussakin, 1962 ; I. palpalis Barnard, 1914 ; I. perplexus Menzies, 1962 ; I. picta Kussakin & Mezhov, 1979 ; I. punctulata Kussakin & Mezhov, 1979 ; I. serricaudis Gurjanova, 1936 ; I. setifera Gurjanova, 1950 ; I. tridens Menzies, 1952 .

Not Ianiropsis varians Winkler & Brandt, 1993 (= Iathrippa varians ( Winkler & Brandt, 1993) , new combination).

Diagnosis. Head frontal margin width between antennulae near basal width of antennae (except I. setifera ). Eyes dorsolateral, large, posterior margin with distinct gap between pereonite 1. Maxilliped endite with 2 receptaculi. In some species the maxilliped palp and/or the pereopod I is sexually dimorphic. Maxilliped palp of adult (terminal) male longer than antennule, projecting anteriorly, visible on head in dorsal view. Pereopod I of adult (terminal) male basis-merus elongate, distinctly longer than those on posterior pereopods; carpus setose, ventral margin proximal to palm approximately linear, slightly sinuous; propodus ventral margin without spines; dactylus well developed. Pereopods II–VII not sexually dimorphic; coxa anterolateral margin rounded (unknown in several species). Pleopod I of adult male lateral lobe distal margin absent (or nearly so); medial lobe without distinct indentation at inner margin of lateral lobe. Pleopod II of adult male stylet curving laterally with no inflections. Pleopod III endopod with 3 (rarely 2) plumose setae, exopod with 2 articles, distally rounded or pointed with 1–3 simple setae. Uropods rami crossectional shape oval.

Distribution. Cosmopolitan, mostly temperate to cold temperate coastal waters.

Remarks. Ianiropsis species have several characteristics that ease their identification, despite the general similarities of most juveniles and females in species of the core taxa of the janirids. Key among these are the fairly consistent shape of the male pleopod I distal tip, and the elongate pereopod I of the males. These characters exclude the species Ianiropsis varians Winkler & Brandt, 1993 from Ianiropsis . We therefore propose a new combination, Iathrippa varians ( Winkler & Brandt, 1993) . Other characters that support this new combination are as follows. All species of Ianiropsis , including both sexes, have a narrow pleopod III exopod, which is distinctly different from the broad exopod found in Iathrippa . The broad exopod of Iathrippa is related to the partially opercular condition of this pleopod ( Wilson, 1987). The Ianiropsis male pleopod II protopod has a distinct extension posterior to the exopod, while in Iathrippa it is abbreviated, owing to its nonopercular form. The terminal margin of the male pleopod I is consistent across the species within each genus, so that the projecting medial lobes of the species I. varians clearly places it with Iathrippa . This species was described without the characteristic rostrum, but our experience with Australian Iathrippa suggests that the rostrum can be variable between species in the genus Iathrippa . The rostrum can also be thin and hard to see in some species. Regarding more general body form characters, Iathrippa species have a broad body and eyes that project substantially from the head as in I. varians , whereas Ianiropsis species have narrow bodies and eyes that are more dorsal in position, with some separation from the head lateral margin.