Terebellides kongsrudi, Parapar & Capa & Nygren & Moreira, 2020

Parapar, Julio, Capa, Maria, Nygren, Arne & Moreira, Juan, 2020, To name but a few: descriptions of five new species of Terebellides (Annelida, Trichobranchidae) from the North East Atlantic, ZooKeys 992, pp. 1-58 : 1

Terebellides kongsrudi sp. nov. Figs 1 , 2 , 3C , 4C , 8C , 9 , 11 , 12 , 17B , 28A ; Table 1; Suppl. material 1: Table S1; Suppl. material 2: Table S2

Species 13 - Nygren et al. 2018: 18-22, figs 6, 10.

Material examined.

Type material. Holotype: GNM14632. Paratypes (20 specs): Barents Sea (ZMBN116409, ZMBN116411, ZMBN116414); Norwegian coast and shelf (ZMBN116412, ZMBN116413, ZMBN116415, ZMBN116416, ZMBN116417, ZMBN116418, NTNU-VM66568, NTNU-VM66570, NTNU-VM66571, NTNU-VM66572, NTNU-VM68195, NTNU-VM72560, NTNU-VM72561, NTNU-VM72562, NTNU-VM72563); Skagerrak (GNM15136, GNM14632, GNM14638).

Holotype. Complete specimen, 50.0 mm long and 5.0 mm width (Figs 3C , 4C ).

GenBank accession numbers of material examined (COI).

Paratypes: MG025201, MG025202, MG025203, MG025204, MG025210, MG025211, MG025212, MG025214, MG025216, MG025217, MG025218, MG025219, MG025223. Additional material: MG025199, MG025200, MG025205, MG025206, MG025207, MG025208, MG025209, MG025213, MG025215, MG025220, MG025221, MG025222, MG025224.

Diagnostic features of type material.

Complete individuals 12.0-50.0 mm in length (Fig. 17B ). Branchial dorsal lobes lamellae without papillary projections. Ventral branchial lobes hidden in between dorsal ones (Figs 3C , 4C , 11A-C ). Lateral lappets and dorsal projection of thoracic notopodia on TC2(3)-TC5(4) (Fig. 11A ). Geniculate chaetae in TC6, acutely bent, with low marked capitium (Fig. 12A, B ). Two pairs of nephridial pores in TC4 and TC5 and ciliated papilla dorsal to thoracic notopodia (Fig. 11D, E ). Thoracic uncini in one row with rostrum/capitium length ratio approximately 2: 1 and capitium with a first row of 2-5 medium-sized teeth, followed by several smaller teeth (Fig. 12C-E ). Abdomen with 25-35 uncinigers (Fig. 12F ) with type 1 uncini (Figs 12G , 28A ).

Nucleotide diagnostic features.

All sequences of T. kongsrudi sp. nov. share the unique apomorphic nucleotides in positions 300 (G) and 624 (G) of our alignement.

Type locality.

Skagerrak; 429-445 m deep (Fig. 8C ; Suppl. material 1: Table S1).

Distribution and bathymetry.

Barents Sea, Greenland Sea, along the Norwegian coast and shelf, reaching the Skagerrak to the South; 108-534 m deep ( Nygren et al. 2018) (Figs 8C , 9 ; Suppl. material 1: Table S1).

Etymology.

This species is named after Dr. Jon Anders Kongsrud, Department of Natural History, Zoological Museum Bergen-ZMB (Norway), housing institution of some of the specimens used in the present study, for his dedication to the study of Norwegian polychaetes and his friendship.

Remarks.

This is a large species reaching up to 50.0 mm long, and is characterised by the presence of ciliated papilla dorsal to thoracic notopodia, lack of papillae on the margins of branchial lamellae, thoracic uncini of type 3 and abdominal uncini of type 1. These features are also shared by species 12 (sensu Nygren et al. 2018), which will be described elsewhere (Gaeva and Jirkov, pers. comm.). Terebellides kongsrudi sp. nov. is also morphologically similar to T. bakkeni sp. nov. (see above) but T. kongsrudi sp. nov. and species 12 show a wider geographic distribution; on the contrary, species 12 is present at shallower depths (<200 m) while T. kongsrudi sp. nov. extends to deeper depths (>500 m).

Finally, in the 26 sequences belonging to this species (see Suppl. material 2: Table S2), there were fourteen haplotypes showing 0-1.9% of intraspecific divergence, and a minimum of 8.2% uncorrected genetic distance with members of species 12 which is the closest relative (sensu Nygren et al. 2018).

Figures

Figure 1. Phylogenetic tree after Maximum Likelihood analyses on a concatenated dataset of cox 1, 16 S rDNA, ITS 2, and 28 S rDNA (as in Nygren et al. 2018). Bootstrap support values above nodes. Coloured squares indicate the major clades referred herein as Groups A-D. Within Group A, the focus of present study, subgroups A 1 - A 4 and species 6 - 13, 18 - 21, 23, 28 are labelled.

Figure 2. Phylogenetic tree after Maximum Likelihood analyses on a dataset of cox 1 (including all sequences in Nygren et al. 2018 and in Lavesque et al. 2019). Bootstrap support values above nodes. Species other than members of Group A are collapsed. Species with names refer to those dealt with in present study.

Figure 3. STM photographs of several Terebellides species. A Terebellides bakkeni sp. nov. (species 10; holotype, ZMBN 116395) B Terebellides stroemii Sars, 1835 (species 11; non-type specimen, ZMBN 116397) C Terebellides kongsrudi sp. nov. (species 13; holotype, GNM 14632) D Terebellides bigeniculatus Parapar, Moreira & Helgason, 2011 (species 20 + 28; non-type specimen, ZMBN 116514) E Terebellides europaea Lavesque, Hutchings, Daffe, Nygren & Londono-Mesa, 2019 (species 6; non-type specimen, GNM 14628) F Terebellides ronningae sp. nov. (species 7; holotype, ZMBN 116357) G Terebellides norvegica sp. nov. (species 8; holotype, ZMBN 416378) H Terebellides scotica sp. nov. (species 9; holotype, ZMBN 116385). Abbreviations: bdl - branchial dorsal lobe; bvl - branchial ventral lobe; TC - thoracic chaetiger.

Figure 4. Line drawings of several Terebellides species. A Terebellides bakkeni sp. nov. (species 10; holotype, ZMBN 116395), anterior end, right lateral view B Terebellides stroemii Sars, 1835 (species 11; non-type specimen, ZMBN 116397), anterior end, right lateral view C Terebellides kongsrudi sp. nov. (species 13; holotype, GNM 14632), anterior end, left lateral view D Terebellides bigeniculatus Parapar, Moreira & Helgason, 2011 (species 20 + 28; non-type specimen, ZMBN 116514), anterior end, left lateral view. Abbreviations: bdl - branchial dorsal lobe; bvl - branchial ventral lobes; dpn - dorsal projection of notopodium; TC - thoracic chaetiger.

Figure 8. Geographic distribution of A T. bakkeni sp. nov. B T. stroemii Sars, 1835 C T. kongsrudi sp. nov. D T. bigeniculatus Parapar, Moreira & Helgason, 2011.

Figure 9. Bathymetric distribution of Terebellides species studied in this work. Subgroups (A 1 - 3) within group A sensu Nygren et al. (2018) are indicated.

Figure 11. Terebellides kongsrudi sp. nov. (species 13; paratypes, ZMBN 116409 and ZMBN 116411), SEM micrographs. A anterior end, left lateral view B branchiae, left side C anterior end, left lateral view D TC 1 and TC 2, thoracic dorsal papillae E TC 3, thoracic dorsal papilla (framed in C) F several thoracic chaetigers, left lateral view. Abbreviations: abl - anterior branchial lobe; bdl - branchial dorsal lobe; bdltp - branchial dorsal lobe terminal papilla; dpn - dorsal projection of notopodium; tdp - thoracic dorsal papilla; tll - thoracic lateral lobes.

Figure 12. Terebellides kongsrudi sp. nov. (species 13; paratype, ZMBN 116409), SEM micrographs. A TC 6 (TU 1) geniculate chaeta B detail of geniculate chaeta (arrow pointing to capitium) C-E thoracic uncini, lateral and frontal views (arrow in D pointing to rostrum curved at distal end) F abdominal unciniger G abdominal uncini, frontal view (framed in F).

Figure 17. Relationship between number of abdominal chaetigers and body length (complete specimens) for Terebellides species described in this work.

Figure 28. SEM micrographs of abdominal uncini types of Terebellides species. A T. kongsrudi sp. nov. (species 13; ZMBN- 116409) B T. bigeniculatus Parapar, Moreira & Helgason, 2011 (species 20 + 28; ZMBN- 116513) C T. ronningae sp. nov. (species 7; ZMBN- 116353) D Terebellides stroemii Sars, 1835 (species 11; ZMBN- 116399). Abbreviations: ctr - capitium teeth row; ros - rostrum.