Scottocheres Giesbrecht, 1987

Canário, Roberta, Farias, Amilcar, Neves, Elizabeth & Johnsson, Rodrigo, 2022, Description of a new Scottocheres Giesbrecht, 1897 (Copepoda, Siphonostomatoida Asterocheridae), including an emended diagnosis and key for the genus, Zootaxa 5222 (3), pp. 277-284 : 278-283

Scottocheres Giesbrecht, 1987

Emended diagnosis: Body elongated, cylindrical, thoracic somites without lateral projections. Rostrum absent. Female and male urosome with 3 to 4 and 4 to 5 somites, respectively. Female antennule 17 to 19-segmented, with one segment after the aesthetasc, or 2, as in S. latus . Male antennule 16-segmented with 12 supplementary aesthetascs. Antenna with exopod 1-segmented and endopod 3-segmented. Siphon forming long and thin tube. Mandibular palp absent. Maxillule with 3 setae on each lobe. Outer lobe smaller than inner one. Third exopodal segment of legs 1 to 4 with 4 plumose setae on each. Third endopodal segment of legs 1 to 4 with 6, 6, 5-6 and 4 setae, respectively. Leg 5 with basoendopod, with inner seta representing the endopod and flattened exopod, 1-segmented and armed with 3 setae. Egg sacs paired, ventral, ellipsoidal, with 3 to 5 eggs each.

Remarks: When defining the diagnosis for Scottocheres, Giesbrecht (1899) described a female antennule as having 17 or 18 segments. However, Nicholls (1944) and Malt (1991) described species with 19-segmented antennules, S. latus , and S. stocki , respectively. To accommodate these Scottocheres species, it was necessary to revise the diagnosis to include 19-segmented antennules as well.

Key to the species of Scottocheres :

1. Antennule 17-segmented............................................................................... 2 Antennule 18-segmented............................................................................... 5 Antennule 19-segmented............................................................................... 8

2. Third exopodal segment of leg 1 with three spines on outer margin.............................................. 3 Third exopodal segment of leg 1 with two spines on outer margin............................... S. spinoparva n. sp.

3. Maxillipedal endopod with formula 0,1,1+claw............................................................. 4 Maxillipedal endopod with formula 2,1,1+claw............................................ S. laubieri Stock, 1967

4. Caudal rami longer than wide ......................................................... S. gracilis Hansen, 1923 Caudal rami wider than long............................................. S. elongatus (Scott T. & Scott A., 1894)

5. 2-segmented antennal endopod.......................................................................... 6 3-segmented antennal endopod...................................................... S. youngi Johnsson, 2002

6. Exopod of the antenna with one setae................................................ S. stylifer Giesbrecht, 1902 Exopod of the antenna with more than one setae............................................................. 7

7. Exopod of the antenna with two setae.............................................. S. longifurca Giesbrecht, 1897 Exopod of the antenna with three setae.............................................. S. mipoensis Kim I.H., 2016

8. Second endopodal segment of leg 1 with one inner seta........................................ S. stocki Malt, 1991 Second endopodal segment of leg 1 with two inner setae..................................... S. latus Nicholls, 1944