Nereis

Ramírez-Hernández, Adriana, Hernández-Alcántara, Pablo & Solís-Weiss, Vivianne, 2015, Nereis alacranensis, a new species of polychaete (Annelida, Nereididae) from Alacranes Reef, southern Gulf of Mexico, with a key to Nereis from the Grand Caribbean, Zootaxa 4012 (1), pp. 156-166 : 163-164

Key to the Grand Caribbean species of Nereis

(Modified and updated1, 2 from González-Escalante & Salazar-Vallejo (2003))

1 Parapodial rami very long; four tiny eyes; areas VII–VIII with 30 cones................ N. caymanensis Fauchald, 1977a

- Parapodial rami short; eyes variable; areas VII–VIII variable.................................................. 2

2 Dorsal cirri shorter than notopodial dorsal ligules............................................................ 3

- Dorsal cirri longer than notopodial dorsal ligules............................................................ 5

3 Smooth jaws; longest tentacular cirri extends to chaetiger 5............................. N. anodonta Schmarda, 1861

- Denticulate jaws; longest tentacular cirri longer, extend beyond chaetiger 5....................................... 4

4 Anterior notopodia with two ligules; pharynx with paragnaths only on areas II, IV and VI......... N. grayi Pettibone, 1956

- Anterior notopodia with three ligules; pharynx without paragnaths on area V; areas VII–VIII with five cones............................................................................................ N. goajirana Augener, 1933

5 Longest tentacular cirri extend to chaetiger 5............................................................... 6

- Longest tentacular cirri extend at least to chaetiger 6........................................................ 16

6 Anterior notopodia with rounded ligules.................................................................. 7

- Anterior notopodia with triangular ligules................................................................ 15

7 Area V with paragnaths; notopodial falcigers with blade short, entire and erect, without distal tooth................................................................................................. N. largoensis Treadwell, 1931

- Area V without paragnaths; notopodial falcigers with blade and distal tooth variable in shape........................ 8

8 Area I with paragnaths; blade of notopodial falciger with a distal tooth........................................... 9

- Area I without paragnaths; blade of notopodial falciger bifid.................................................. 13

9 Notopodial falcigers with blade short and several coarse teeth near the base..................................... 10

- Notopodial falcigers with blade long and margin finely dentate, distal tooth markedly recurved...................... 11

10 Blade of notopodial falcigers with four marginal teeth, distal tooth slightly recurved........... N. zonata Malmgren, 1867

- Blade of notopodial falcigers with several coarse marginal teeth, distal tooth straight........... N. pelagica Linnaeus, 1758

11 Area I with 2–3 cones, areas VII–VIII with 2 irregular rows of 50 or less cones of the same size................................................................................................... N. occidentalis Hartman, 1945 3

- Area I with 1–2 cones; areas VII–VIII with 2–4 irregular rows of median cones.................................. 12

12 Dorsal cirrus medially inserted on notopodial dorsal ligule, ventral cirrus basally inserted; dorsal and ventral cirri subequal................................................................................. N. falsa Quatrefages, 1866

- Dorsal and ventral cirri basally inserted, dorsal cirri long................................. N. callaona ( Grube, 1857)

13 Areas VII–VIII with 4–6 cones; 2 eyes visible dorsally, the posterior ones covered by peristomium................................................................................................ N. panamensis Fauchald, 1977b

- Areas VII–VIII with 7–8 cones; 4 eyes visible dorsally...................................................... 14

14 Prostomium deeply notched between the antennae....................................... N. falcaria ( Willey, 1905)

- Prostomium entire anteriorly....................................................... N. jacksoni Kinberg, 1866

15 Area V without paragnaths; longest tentacular cirri extend to chaetiger 3; short blade of notopodial falcigers with up to 7 mar- ginal small teeth; a coarse arc shaped plate on the external ventral side of the peristomium.......... N. alacranensis n. sp.

- Area V with paragnaths; longest tentacular cirri extend to chaetiger 4....................... N. allenae Pettibone, 1956

16 Anterior notopodia with rounded ligules.................................................................. 17

- Anterior notopodia with triangular ligules................................................................ 20

17 Longest tentacular cirri extend to chaetiger 7; notopodial falcigers with long blades and expanded curved tips; areas VII–VIII with medium and small cones in both rows........................................... N. oligohalina ( Rioja, 1946)

- Longest tentacular cirri extend at least to chaetiger 8........................................................ 18

18 Dorsal cirri prominent; dorsal cirri of chaetigers 4 to 7 with apex inflated................ N. caudipunctata ( Grube, 1857)

- Dorsal cirri longer than notopodial ligule but not prominent.................................................. 19

19 Longest tentacular cirri extend to chaetiger 8; area I with 5 cones in group, area V with 2 large cones; reddish brown or olive brown pigmentation on anterior third of body and a dorsal band, more or less bright........... N. victoriana Augener, 1918

- Longest tentacular cirri extend to chaetiger 11; area I with 15 cones in group, area V with 1 large cone; black spot on dorsal side of anterior third of body, transverse bands on each segment, prostomium with two longitudinal bands, central area with no spots, medial surface of palps with a dark spot................. N. garwoodi González-Escalante & Salazar-Vallejo, 2003

20 Anterior pair of eyes crescent-shaped............................................. N. arroyensis Treadwell, 1901

- All eyes rounded.................................................................................... 21

21 Areas VII–VIII with 5–6 cones in single row; area V without paragnaths; area VI with 9 cones....... N. riisei Grube, 1857

- Areas VII–VIII with 2–5 rows of paragnaths; area V with paragnaths........................................... 22

22 Areas VII–VIII with 2 rows of paragnaths; area V with up to 4 cones; anterior notopodia with three ligules............................................................................................... N. lamellosa Ehlers, 1868

- Areas VII–VIII with 3–5 rows of paragnaths; area V with 1–2 cones; anterior notopodia with two ligules.................................................................................................... N. rigida Grube, 1857