Terebellides congolana

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: 18-23

publication ID

https://doi.org/10.11646/zootaxa.4771.1.1

publication LSID

lsid:zoobank.org:pub:A46FAF72-6F95-4DA3-A41D-FE770D6EDF1F

DOI

http://doi.org/10.5281/zenodo.3816145

persistent identifier

http://treatment.plazi.org/id/03BF4239-FFE4-FFDF-EAF8-C0DB9D1AFD48

treatment provided by

Plazi

scientific name

Terebellides congolana
status

sp. nov.

Terebellides congolana  sp. nov.

Figures 11AView FIGURE 11, 12AView FIGURE 12, 13−15View FIGURE 13View FIGURE 14View FIGURE 15, 37View FIGURE 37; Tables 1, 2 urn:lsid:zoobank.org:act:F56164BC-1B78-4ECE-ACA5-543E5D75EB90

Material examined. Type material. Four specimens: holotype ( MNCN 16.01View Materials /18582); three paratypes ( MNCN 16.01View Materials /18581, 16.01/18583 and 16.01/18584, Table 1)  .

Diagnosis. Body large (31–33 mm in length), with branchial anterior lobe, posterior ventral lobes much smaller than dorsal ones, with short terminal filament, and emerging after fusion line of dorsal ones. TC1 notopodia and notochaetae much longer than following ones. Thoracic neurochaetae with rostrum / capitium length about 1/1, and capitium with a first row of 4–5 big teeth followed by a second row of much smaller, progressively smaller teeth.

Description based on holotype

Measurements and general body features. Complete specimen, 31.0 mm long and 3.0 mm wide ( Fig. 12AView FIGURE 12); female with oocytes in body cavity. Body tapering posteriorly, with segments increasingly shorter and crowded towards pygidium. Prostomium compact; large tentacular membrane surrounding mouth with typical buccal tentacles with expanded tips ( Fig. 13A, EView FIGURE 13). SGI as an expanded structure below tentacular membrane ( Fig. 13View FIGURE 13 A–B). Lateral lappets on SGIII–VIII (TC1–6), larger in SGIII–VII (TC1−5) ( Fig. 13View FIGURE 13 A−E). Low oval-shaped glandular region in CH 3 in some specimens ( Fig. 13BView FIGURE 13), but not evident.

Branchiae. Branchiae arising as single structure from SGIII, with a single short-stalked mid-dorsal branch ( Fig. 12AView FIGURE 12, 13View FIGURE 13 A−B, E), one pair of long dorsal (upper) lobes 50% fused, reaching TC6−7 ( Fig. 13CView FIGURE 13) and one pair of ven- tral (lower) lobes about 1/5 as long as dorsal ones), not fused together and arising from mid-length of dorsal lobes fusion line ( Fig. 13View FIGURE 13 A−B). Anterior projection of dorsal lobes (lobe 5) large, about 1/4 length of posterior dorsal lobes ( Fig. 13EView FIGURE 13). Pointed projection of posterior region only in lower lobes, as a short and thick terminal filament ( Fig. 13AView FIGURE 13). Both sides of branchial lamellae with several parallel bent rows of cilia and ciliated papillae on outer edge ( Fig. 14View FIGURE 14 C−D).

Thorax. Eighteen pairs of notopodia (SGIII−XX), with dorsal ciliated papillae ( Fig. 14View FIGURE 14 E−F). TC1 much more developed and with longer notochaetae than subsequent ones ( Fig. 13B, EView FIGURE 13). All notochaetae as simple capillaries. Neuropodia as sessile pinnules from TC6 (SGVIII) to body end, with uncini in single rows starting from TC7 (SGIX) throughout. First neuropodia (TC6) with four sharply bent, acute tipped, geniculate chaetae ( Fig. 15BView FIGURE 15) having minute teeth forming an ill-defined capitium. From TC7, neuropodia with 8−14 uncini per torus in one row, with long-shafted denticulate hooks, rostrum about same length as capitium, with 4−5 big teeth above main fang surmounted by several much smaller denticles ( Fig. 15View FIGURE 15 C−E).

Abdomen. About 40% of body length, with 31 pairs of neuropodia as erect pinnules ( Fig. 15GView FIGURE 15); about 25–30 uncini per torus having four teeth above main fang surmounted by 3–4 teeth in irregular middle row and an upper crest of several smaller teeth ( Fig. 15HView FIGURE 15).

Other body features. One well-developed nephridial papilla behind each TC1 notopodium ( Fig. 14EView FIGURE 14), and two pairs of nephridial openings in TC4 and TC5 ( Fig. 14FView FIGURE 14). Pygidium blunt, funnel-like depression.

Methyl green staining pattern. Anterior CH 1 to CH 9 solid; CH 10 to CH 18 striped; being CH 10 to CH 11 much more marked than following; J-shaped glandular region marked lateral to CH 3; near pattern 5 of Schüller & Hutchings (2010) ( Fig. 37View FIGURE 37).

Variability. Body between 31 and 33 mm in length. Type locality. Off Congo (Table 1). Distribution and bathymetry. Off Congo; sandy mud; 47−167 m depth ( Fig. 11AView FIGURE 11; Table 1). Etymology. The name of the species refers to the type location, the Republic of Congo. Remarks. Terebellides anguicomus Müller, 1858 sensu Solís-Weiss et al. (1991)  resembles T. congolana  sp. nov. in having large sized-branchiae reaching TC6 but differs in having a large transverse dorsal hump on TC5 and 17 thoracic chaetigers (18 in T. congolana  sp. nov. and most species of the genus, see key below).

Terebellides congolana  sp. nov. also differs from other African species in having posterior ventral branchial lobes that are much smaller and located distally, but the following ones also have this character: T. rigel Schüller & Hutchings, 2013  ; T. mediterranea Parapar, Mikac & Fiege, 2013  ; T. akares Hutchings, Nogueira & Carrerette, 2015  , T. persiae  and T. hutchingsae  . However, T. rigel  is a deep-water species (> 2000 m) from the Weddell Sea and does not bear long TC1 notopodia and notochaetae; T. akares  was described from coral reefs (Lizard Island, NE Australia) and has a distinctly short abdomen; T. persiae  is a shallow-water species from the Iranian coast, that has a much more developed anterior branchial lobe and a distinct dorsal hump at TC6; T. hutchingsae  is also a shallow subtidal species from the Gulf of Thailand, that bears geniculate chaetae in two chaetigers, TC5 and TC6, instead of only one in TC6. The closest species to T. congolana  sp. nov. is T. mediterranea  , a shallow-water species (31 m depth) from the Adriatic Sea; it also bears branchiae with a similar shape and very small ventral posterior lobes arising near the distal end of the branchiae, and TC1 notopodia and notochaetae longer than following, but it differs from the new species in having a shorter body (21 mm in length vs. 31 mm in T. congolana  sp. nov.) and a much larger tentacular membrane.

Terebellides europaea Lavesque, Hutchings, Daffe, Nygren & Londoño-Mesa, 2019  , from the French coast of the Bay of Biscay, also shares with T. congolana  sp. nov. the long notopodia and notochaetae of TC1, but it differs from the new species in having papillar projections over the edge on anterior branchial lamellae, much bigger ventral branchial lobes and attached to the branchial stem, and in lacking ciliated papillae in branchial lamellae.