Bryocyclops, Boonyanusith & Sanoamuang & Brancelj, 2018

Boonyanusith, Chaichat, Sanoamuang, La-orsri & Brancelj, Anton, 2018, A new genus and two new species of cave-dwelling cyclopoids (Crustacea, Copepoda) from the epikarst zone of Thailand and up-to-date keys to genera and subgenera of the Bryocyclops and Microcyclops groups, European Journal of Taxonomy 431, pp. 1-30 : 14-16

Key to genera and subgenera of the Bryocyclops group

Common characteristics of the group are the following: a) 10- or 11-segmented antennules; b) rami of swimming legs 2-segmented but with additional oligomerization in some species; c) P5 completely fused with Pd5, with baseoendopodal seta laterally (a remnant of the proximal segment of P5 – coxa, basis and Endp), with 2 setae/spines sub-ventrally (a remnant of the Exp P5).

1. Position of P6 vestiges on the posterior half of genital double-somite ……………………………… ……………………………………………………………………… Haplocyclops Kiefer, 1952 (2)

– Position of P6 vestiges on the anterior half of genital double-somite ………………………………3

2. P1–P4 Exp-2 spine formula 2.3.3.2 …………………… Haplocyclops (Haplocyclops) Kiefer, 1952

– P1–P4 Exp-2 spine formula 2.2.2.2 ………………………………………………………………… …………………………………… Haplocyclops (Kierfercyclops) Karanovic & Ranga Reddy, 2005

3. P5 reduced to one stout spine on Exp lobe; coxa of P4 with one strong, spiniform seta ……………………………………………………………………… Bacillocyclops Lindberg, 1956

– P5 with two setae/spines on Exp lobe ……………………………………………………………4

4. P5 remnant of Exp lobe with one spine and one seta; genital double-somite longer than wide; distal segment of P4 Endp with six elements; one spine and one seta apically … Yansacyclops Reid, 1988

– P5 remnant of Exp lobe with two setae; genital double-somite as long as wide or wider than long …5

5. P1 without median seta/spine on both coxa and basis; anterolateral seta (II) on caudal ramus positioned dorsally; P1–P4 Endp-2 spine formula 2.2.2.2 ……………… Rybocyclops Dussart, 1982

– P1 with one seta/spine on coxa, basis with or without inner seta; anterolateral seta (II) on caudal ramus positioned dorsally or laterally; P1–P4 Endp-2 spine formula not 2.2.2.2 ……………6

6. Male P3 Endp-2 with modified apical spine ………………………………………………………7 ‒ Male P3 Endp-2 without modified apical spine ……………………… Allocyclops Kiefer, 1932 (8)

7. Intercoxal sclerite of P4 with obtuse, slightly rounded prominence; P4 Exp-2 with five setae, P4 Endp distinctly 2-segmented; mandibular palp armed with three setae …………… ……………………………………………………………………………… Siamcyclops gen. nov.

– Intercoxal sclerite of P4 with pointed or rounded prominence; P4 Exp-2 with four (only in B. jankowskajae with five) setae, P4 Endp with variable segmentation: 1-segmented, indistinctly 2-segmented or distinctly 2-segmented; mandibular palp armed with one seta or seta absent ……… …………………………………………………………………………… Bryocyclops Kiefer, 1927

8. Coxa of P1–P4 with seta in inner distal corner ……………………………………………………9 – Coxa of P2–P4 without seta in inner distal corner … Allocyclops (Stolonicyclops) Reid & Spooner, 1998

9. Antenna with seta representing Exp; P4 Endp-2 with one apical spine and one outer seta ……… ………………………………………………………… Allocyclops (Psammocyclops) Kieffer, 1955

– Antenna without seta representing Exp; P4 Endp-2 with two apical spines ……………………… ……………………………………………………………… Allocyclops (Allocyclops) Kieffer, 1932