Terebellides

Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., Zootaxa 4771 (1), pp. 1-61 : 55-56

Key to intertropical South Atlantic species of Terebellides

The following key comprises the eight species described here, together with those previously described or recorded from Western Atlantic ( Williams, 1984; Solís-Weiss et al., 1991; Garraffoni & Lana, 2003; Díaz-Díaz & Liñero- Arana, 2003), Caribbean Sea ( Williams, 1984) and southern Brazil ( Bremec & Elías, 1999; Garraffoni & Lana, 2003; Schüller & Hutchings, 2012). No material of these species was examined; characters were obtained from bibliography. It is mostly based on branchial characters, number of thoracic chaetigers and location of geniculate chaetae, but also on the thoracic colouration, presence of dorsal hump, and length of thoracic notochaetae.

Terebellides banalis Schüller & Hutchings, 2012 and Terebellides bulbosa Schüller & Hutchings, 2012 are not considered here because the original descriptions do not provide detailed information on branchiae. In T. banalis , only one type specimen has branchiae, consisting of a stout stem with four very small and stout branchial lobes ( Schüller & Hutchings, 2012: Fig. 7A , 8B ), suggesting it may be a juvenile. The species is characterized by having well-developed S2, ventrally wider than S3 (TC1), and by TC6 cane-shaped geniculate chaetae ( Schüller & Hutchings, 2012: Fig. 8E ). Terebellides bulbosa bears a branchial stem lacking well defined lobes and shows very large lappets in the first four chaetigers, followed by a series of laterally expanded segments before a typical Terebellides - like posterior thorax ( Schüller & Hutchings, 2012: Fig. 10 ).

1. First unciniger in TC5; 17 or 18 thoracic uncinigers.......................................................... 2

- First unciniger in TC6; 18 thoracic uncinigers............................................................... 3

2. 17 thoracic uncinigers............................................................. T. anguicomus Müller, 1858

- 18 thoracic uncinigers....................................................... T. crux Schüller & Hutchings, 2013

3. Anterior dorsum with a distinct hump on TC7............................................................... 4

- Anterior dorsum smoothly curved........................................................................ 5

4. Ventral branchial lobes more slender than dorsal ones; lateral lappets from TC3 to TC5.................................................................................. T. carmenensis Solís-Weiss, Fauchald & Blankensteyn, 1991

- Both branchial lobes similar in size; lateral lappets from TC5 to TC7..................... T. totae Bremec & Elías, 1999

5. TC1 to TC5 ventrally whitish ( Fig. 33 A–B)........................................... Terebellides ramili sp. nov.

- TC1 to TC4 similar in colour as following chaetigers......................................................... 6

6. Anterior branchial lobe well developed.................................................................... 7

- Anterior branchial lobe absent or much shorter than posterior lobes............................................. 13

7. Branchial stem long, about as long as posterior dorsal lobes ( Fig. 21A )................. Terebellides kirkegaardi sp. nov.

- Branchial stem much shorter than posterior dorsal lobes....................................................... 8

8. TC1 notopodia and notochaetae much more developed than following........................................... 9

- TC1 notopodia and notochaetae similar to following........................................................ 10

9. Ventral posterior branchial lobes length about 10% of dorsal ones, located after the fusion line of the latter ( Fig. 12A , 13A )............................................................................ Terebellides congolana sp. nov.

- Ventral posterior branchial lobes length about 50% of dorsal ones, emerging directly from the branchial stem ( Fig. 12B , 16C )............................................................................. Terebellides fauveli sp. nov.

10. Thoracic notochaetae almost as long as thoracic width; TC1 lateral lappet forming a fan-like dorsal expansion ( Fig. 21B , 25 B–C)..................................................................... Terebellides longiseta sp. nov.

- Thoracic notochaetae much shorter than thoracic width; TC1 lateral lappet not forming a fan-like dorsal expansion....... 11

11. TC1 notochaetae short, scarce................................. T. lanai Solís-Weiss, Fauchald & Blankensteyn, 1991

- TC1 notochaetae similar to following ones................................................................ 12

12. 20–26 abdominal chaetigers.......................... Terebellides parvus Solís-Weiss, Fauchald & Blankensteyn, 1991

- At least 30 abdominal chaetigers...................................................... T. klemani Kinberg, 1867

13. Branchial lobes neither fused nor comma-shaped........................................................... 14

- Branchial lobes at least partially fused, comma-shaped....................................................... 19

14. Branchial posterior ventral lobes with long terminal filament ( Fig. 28A , 30 A–B)............. Terebellides nkossa sp. nov.

- Branchial posterior ventral lobes lacking long terminal filament............................................... 15

15. Anterior thoracic chaetigers narrow, laterally expanded like a partially compressed accordion.................................................................................... Terebellides concertina Schüller & Hutchings, 2012

- Anterior thoracic chaetigers different..................................................................... 16

16. Lower buccal lip and tentacular membrane greatly expanded.................................................. 17

- Lower buccal lip and tentacular membrane different......................................................... 18

17. Branchial lobes completely free from each other, bearing few and loose lamellae; upper lip of tentacular membrane small................................................................... Terebellides diva Schüller & Hutchings, 2012 Branchial lobes not fused but well defined, with numerous and well-packed lamellae; upper lip of tentacular membrane much developed ( Fig. 35 A–B)................................................................... Terebellides sp. 1

18. Pygidium with two prominent lateral papillae.......................... Terebellides gingko Schüller & Hutchings, 2012

- Pygidium lacking papillae......................................... Terebellides sepultura Garraffoni & Lana, 2003

19. Branchial posterior ventral lobes similar in shape to dorsal ones, about half longer, located at base of dorsal ones ( Fig. 2B , 8E ); thoracic uncini capitium with first row of 5–6 teeth, similar in size to following ones ( Fig. 10 A–B)................................................................................................. Terebellides augeneri sp. nov.

- Branchial posterior ventral lobes much shorter than dorsal ones................................................ 20

20. Branchial posterior ventral lobes near distal end of dorsal ones ( Fig. 2A , 4A , 5A ); thoracic uncini capitium with first row of 1–2 teeth, much bigger than following ( Fig. 7A ).......................... Terebellides africana Augener, 1918 stat. prom.

- Branchial posterior ventral lobes emerging at base of dorsal ones.......... Terebellides malvinensis Bremec & Elías, 1999

Figures

FIGURE 2. Terebellides africana Augener, 1918 stat. prom. (lectotype, ZMH V1709): (A) anterior end, left lateral view and detail of branchiae. Terebellides augeneri sp. nov. (holotype, MNCN 16.01/18579): (B) anterior end, left lateral view and detail of branchiae. Abbreviations: bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; bt—buccal tentacle; TC—thoracic chaetiger.

FIGURE 4. Terebellides africana Augener, 1918 stat. prom. Stereomicroscope images of anterior end views of non-type specimens from Gold Coast and Nigeria (NHMD-231453, NHMD-231455 and NHMD-231458). (A) right lateral; (B–C) left lateral; (D) ventral. Abbreviations: abl—anterior branchial lobe; bdlfl—branchial dorsal lobes—fusion line; bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bst—branchial stalk; pcop—parasitic copepod; TC—thoracic chaetiger; TN—thoracic notopodium.

FIGURE 5. Terebellides africana Augener, 1918 stat. prom. SEM micrographs of the non-type specimen NHMD-636918. (A) anterior end, left lateral view; (B) branchial lamellae, detail; (C) TC1 and TC2 dorsal projections and nephridial pore. In (A), squares showing several branchial lamellae and TC1 and TC2, shown at higher magnification in (B) and (C) respectively; broken line circles showing position of nephridial openings in (A) and nephridial papilla in (C). Abbreviations: bcp—branchial ciliated papilla; bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; loli—lower lip; no—nephridial opening; np—nephridial papilla; TC—thoracic chaetiger; tc2ll—thoracic chaetiger 2 lateral lappet; tc1dpr—thoracic chaetiger 1 dorsal projection; tc3dpr—thoracic chaetiger 3 dorsal projection; TN—thoracic notopodium; TU—thoracic unciniger.

FIGURE 7. Terebellides africana Augener, 1918 stat. prom. SEM micrographs of the non-type specimen NHMD-636918. (A) row of several thoracic uncini, upper view; (B) one thoracic uncinus, lateral view; (C) typical row of thoracic uncini, lateral view. Circles in (A) showing number of teeth on capitium.

FIGURE 8. Terebellides augeneri sp. nov. Stereomicroscope images of holotype (MNCN 16.01/18579) (A–C) and paratype (NHMD-636919) (D–E). (A) full specimen, ventral view; (B) anterior end, dorsal view; (C) anterior end, ventral view; (D) anterior end, ventral view; (E) anterior end, dorsal view. Abbreviations: bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bst—branchial stalk; latlap—lateral lappet; SG—segment; TC—thoracic chaetiger.

FIGURE 10. Terebellides augeneri sp. nov. SEM micrographs of the paratype MNCN 16.01/18578. (A) row of thoracic uncini, upper view; (B) two thoracic uncini, upper-lateral view; (C) TC6 geniculate chaeta, upper view; (D) the same, capitium, detail (framed in C); (E) abdominal uncini, upper view; (F) abdominal uncini, frontal view. Circles in (B) and (E) showing number of teeth on capitium. Abbreviations: cap—capitium; ros—rostrum.

FIGURE 12. Terebellides congolana sp. nov. (holotype, MNCN 16.01/18582): (A) anterior end, left lateral view and detail of branchiae. Terebellides fauveli sp. nov. (holotype, NHMD-636920): (B) anterior end, right lateral view and detail of branchiae. Abbreviations: bdltp—branchial dorsal lobe terminal papilla; bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bvltf—branchial ventral lobe terminal filament; loli—low- er lip; TC—thoracic chaetiger; tnc—thoracic notopodial chaetae.

FIGURE 13. Terebellides congolana sp. nov. Stereomicroscope images of anterior end of holotype (B, MNCN 16.01/18582) and two paratypes (A, C–E, MNCN 16.01/18581 and 16.01/18583). (A) right latero-ventral view and detail of branchia ventral lobes; (B) left lateral view and detail of TC1 notochaetae; (C) dorsal view; (D–E) left lateral view. Abbreviations: abl—anterior branchial lobe; bdlfl—branchial dorsal lobes—fusion line; bldl—branchial left dorsal lobe; bdltp—branchial dorsal lobe terminal papilla; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bvltp—branchial ventral lobe terminal papilla; dh—dorsal hump; latlap—lateral lappet; loli—lower lip; no—nephridial opening; SG—segment; TC—thoracic chaetiger; tc1not—thoracic chaetiger 1 notopodium; tc3gr—thoracic chaetiger 3 glandular region; tnc—thoracic notopodial chaetae; TU—thoracic unciniger.

FIGURE 16. Terebellides fauveli sp. nov. from Ivory Coast. Stereomicroscope images of anterior end. Holotype (A, NHMD- 636920) and several paratypes (B-D, NHMD-636921). (A) right lateral view; (B–D) left lateral views. Abbreviations: bdltpbranchial dorsal lobe terminal papilla; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; bvltf—branchial ventral lobe terminal filament; SG—segment; TC—thoracic chaetiger; TN—thoracic notopodium; TU—thoracic unciniger.

FIGURE 21. Terebellides kirkegaardi sp. nov. (holotype, NHMD-231439): (A) anterior end, left lateral view and detail of branchiae. Terebellides longiseta sp. nov. (holotype, NHMD-231459): (B) anterior end, left lateral view and detail of branchiae. Abbreviations: abl—anterior branchial lobe; bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bst—branchial stalk; TC—thoracic chaetiger; tnc—thoracic notopodial chaetae.

FIGURE 25. Terebellides longiseta sp. nov. Stereomicroscope images. Holotype (NHMD-231459): (A) anterior end, right lateral view; (B) branchial lobes and TC1–2 notopodia, right lateral view. Paratype (NHMD-231448): (C) anterior end, left lateral view. Holotype (NHMD-231459): (D) branchiae, postero-dorsal view. Abbreviations: abl—anterior branchial lobe; bldl—branchial left dorsal lobe; TN—thoracic notopodium.

FIGURE 28. Terebellides nkossa sp. nov. (holotype, MNCN 16.01/18594): (A) anterior end, left lateral view and detail of branchiae. Terebellides ramili sp. nov. (holotype, MNCN 16.01/18615): (B) anterior end, left lateral view and detail of branchiae. Abbreviations: bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bvltf—branchial ventral lobe terminal filament; TC—thoracic chaetiger.

FIGURE 30. Terebellides nkossa sp. nov. SEM micrographs of the paratype MNCN 16.01/18596. (A) anterior end, left dorsolateral view; (B) branchial posterior ventral lobes, ventral view; (C) several dorsal branchial lamellae, inner side, showing ciliature pattern; (D) the same, rows of cilia, detail; (E) TC1–TC5, left lateral view; (F) TC1 nephridial opening. Abbreviations: bct—branchial ciliated tuft; bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bst—branchial stalk; bt—buccal tentacle; bvltf—branchial ventral lobe terminal filament; cr—ciliary row; latlap—lateral lappet; loli—lower lip; no—nephridial opening; np—nephridial papilla; TN—thoracic notopodium; tndp—thoracic notopodium dorsal papilla.

FIGURE 33. (A–B) Terebellides ramili sp. nov. Stereomicroscope images of holotype MNCN 16.01/186013. (A) full specimen, right lateral view; (B) anterior end, left lateral view. Terebellides af. ramili (NHMD-231438): (C) anterior end, right lateral view. Abbreviations: bldl—branchial left dorsal lobe; blvl—branchial left ventral lobe; brdl—branchial right dorsal lobe; brvl—branchial right ventral lobe; bvltf—branchial ventral lobe terminal filament; gc—geniculate chaetae; loli—lower lip; ooc—oocytes; SG—segment; TC—thoracic chaetiger; tm—tentacular membrane.

FIGURE 35. Terebellides sp. 1 (NHMD-231440), stereomicroscope images. (A) anterior end, left latero-dorsal view; (B) branchiae and tentacular membrane, detail. Terebellides sp. 2 (NHMD-231449), stereomicroscope images. (C) full specimen, right lateral view; (D) anterior end, right lateral view. Abbreviations: bldl—branchial left dorsal lobe; brdl—branchial right dorsal lobe; bvltp—branchial ventral lobe terminal papilla; loli—lower lip; ooc—oocytes; TC—thoracic chaetiger; tm—tentacular membrane.