Spectrarcturus, Schultz, 1981

Stransky, Bente, Svavarsson, Jörundur, Poore, Gary C. B. & Kihara, Terue Cristina, 2020, Revision of Pleuroprion zur Strassen, 1903 (Holidoteidae) and re-evaluation of Spectrarcturus Schultz, 1981 (Arcturidae) (Crustacea, Isopoda, Valvifera), Zootaxa 4894 (1), pp. 1-52 : 15

Key to species of Spectrarcturus (females)

1a Posterior end of pleotelson bifid.......................................................................... 2

1b Posterior end of pleotelson rounded, pointed or truncated...................................................... 4

2a Distolateral spine on article 3 of antenna about as long as article width.......................... S. hystrix ( Sars, 1877)

2b Distolateral spine on article 3 of antenna short, much shorter than article width.................................... 3

3a Pleotelson with tubercles on most dorsal surface....................................... S. murdochi ( Benedict, 1898)

3b Pleotelson only with long spines on anterior part.................................. S. intermedius (Richardson, 1899)

4a Pleotelson bluntly truncated, slightly convex apically............................... S. chlebovitschi ( Kussakin, 1972)

4b Pleotelson rounded or pointed apically.................................................................... 5

5a Pleotelson widely rounded apically; body without dense setae.................................................. 6

5b Pleotelson pointed apically; body densely setose............................................................. 7

6a Body with numerous short, rounded tubercles............................... S. iturupicus ( Kussakin & Mezhov, 1979)

6b Body with several long, slender spines on each pereonite................................ S. toporoki ( Kussakin, 1972)

7a Pleotelson distally narrowly pointed; pereonite 4 twice as long as pereonite 3.............. S. fabulosus ( Gurjanova, 1955)

7b Pleotelson distally narrow, tounge-like; pereonite 4 1.7 times as long as pereonite 3........... S. furcatus ( Kussakin, 1982)