Barantolla cryptogenica, Çinar & Dağli & Erdoğan-Dereli, 2022

Çinar, Melih Ertan, Dağli, Ertan & Erdoğan-Dereli, Deniz, 2022, The diversity of polychaetes (Annelida: Polychaeta) in a longterm pollution monitoring study from the Levantine coast of Turkey (Eastern Mediterranean), with the descriptions of four species new to science and two species new to the Mediterranean fauna, Journal of Natural History 56 (33 - 36), pp. 1383-1426 : 1413-1419

Barantolla cryptogenica sp. nov.

( Figures 15–18 )

Type material

Levantine Sea, Turkey, holotype. ESFM-POL/2017-209 , 19 August 2017, MRESW1 , 36.735278°N, 31.46°E, 30 m, sandy mud with shell fragments .

Paratypes. ESFM-POL/2017-210 , 18 August 2017, MERSWR, 36.762222°N, 34.650833°E, 16 m, mud, 2 specimens; ESFM-POL/2019-70 , 06 September 2019, Mersin Bay , off Mersin, 36.671833°N, 34.555558°E, 55 m, mud, 1 specimen; ESFM-POL/2017-211 , 18 August 2017, MERSWR, 36.762222°N, 34.650833°E, 16 m, mud, 67 specimens; ESFM-POL/2017-212 , 16 August 2017, ISKSW2 , 36.521389°N, 35.975833°E, 37 m, mud with shell fragments, 3 specimens .

Non-type material

Levantine Sea, Turkey. ESFM-POL/2018-160 , 15 August 2018, BTCSW1 , 36.862222°N, 35.961944°E, 33 m, mud, 9 specimens; ESFM-POL/2018-161 , 12 August 2018, GRESW2 , 36.282778°N, 34.050278°E, 25 m, mud with shell fragments, 5 specimens; ESFM-POL/2019 - 71, 06 September 2019, Mersin Bay , off Mersin, 36.671833°N, 34.555558°E, 55 m, mud, 11 specimens; ESFM-POL/2019-72 , 25 July 2019, Mersin Bay, off Mersin, 36.671833°N, 34.555558°E, 55 m, mud, 30 specimens; ESFM-POL/2019-73 , 03 September 2019, MERSWR, 36.756133°N, 34.6478°E, 37 m, mud, 3 specimens; ESFM-POL/2019-74 , 04 September 2019, SAMSWR, 36.04845°N, 35.940767°E, 67 m, mud, 19 specimens .

Description

Holotype and paratypes incomplete, with anterior fragments; holotype 3.9 mm long, 15 with chaetigers. Thorax with 11 chaetigers, 2.6 mm long, 0.6 mm wide (chaetiger 2); abdomen 1.3 mm long, 0.4 mm wide, with four chaetigers ( Figures 15 (a), 16(a)).

Prostomium short, small, somewhat semicircular in shape, lobated, without palpode ( Figures 15 (a), 16(a–c)); without eyes; with a pair of distinct nuchal organs situated posterior-lateral sides of prostomium, eversible (everted in some paratypes), lobated, ciliated, almost half size of prostomium ( Figures 16 (c,d), 18(a,b)). Proboscis everted in holotype and some paratypes, globular, covered with dense small papillae ( Figures 15 (a), 16(a,b), 18(a)). Peristomium distint, with one annulation, almost twice length of chaetiger 1.

Thorax cylindrical in cross section, inflated through chaetigers 1–2; epithelium not areolated; with achaetous narrow peristomium and 11 chaetigers; intersegmental grooves indistinct in anterior part, distinct in posterior part ( Figures 15 (a), 16(a)). First 2– 3 chaetigers with two annulations. Lateral organs distinct, ciliated, situated between noto-and neuropodia ( Figures 15 (a), 16(a,e)). Nephridial pores indistinct. Parapodia situated almost in middle part of segments; notopodia on dorso-lateral part, neuropodia on ventro-lateral part of segments. Thoracic chaetigers becoming longer but narrower towards posterior end. Last five thoracic chaetigers slightly biannulated.

Thoracic chaetigers 1–6 with limbate capillary chaetae only ( Figure 15 (b)); chaetiger 1 with only notochaetae, others with noto- and neurochaetae; notopodial capillary chaetae numbering 13; 50–120 µm long; neuropodial capillary chaetae numbering 15–16; 50– 120 µm long. Anterior capillary chaetae shorter than posterior ones. Chaetigers 7–11 with long-handled hooded hooks only; numbering ca. seven hooks on notopodia ( Figures 15 (c), 18(c)), eight hooks in neuropodia ( Figure 15 (d)). Hooks multidentate, with a large main fang, slightly bending ventrally, with three rows of teeth; shafts with a node. Notopodial and neuropodial hooks arranged in a vertical row, node distinct; length between node and tip around 140 µm ( Figure 15 (c)); hoods distinct, widely surrounding tip; length ca. 60 µm; almost 4 times longer than wide, with small opening near tip.

Transition from thorax to abdomen distinct, marked by abrupt broadening of segments and wrinkling of epithelium ( Figures 15 (a), 16(a)).

Abdominal parapodia placed on posterior part of segments; notopodia placed more dorsally and neuropodia more ventrally in abdomen than in thorax; parapodia placed posterior part of segments. Abdominal intersegmental grooves distinct. Lateral organs and nephridial pores indistinct in abdomen. Abdominal chaetigers wide and long in anterior part, becoming narrower and tapering posteriorly.

Abdominal chaetigers with hooded hooks only; numbering almost 7–10 hooks in both noto- and neuropodia ( Figures 15 (e,f), 18(d)); shafts with a distinct node; distal part more curved than that of thoracic hooks; hooks similar in size and shape in both noto- and neuropodia; abdominal hooks much shorter than thoracic ones; length between node and tip almost 80–90 µm in noto- and neuropodial hooks ( Figures 15 (e,f), 17(a–d)). Hooks multidentate, with a curved main fang surmounted by four rows of teeth ( Figures 17 (b,d), 18(d)). Hoods distinct, ca. 40–45 µm long, 4 times longer than wide ( Figure 17 (a–d)).

Branchiae were not observed. Pygidium missing.

Etymology

The specific epithet indicates the alien status of this species, cryptogenic (i.e. a species that could be a native or an alien species).

Remarks

Until now, four Barantolla species have been described in the world’s oceans, all in the Indo-Pacific region ( Read and Fauchald 2022): Barantolla sculpta Southern, 1921 (type locality: India, Indian Ocean, brackish, shallow water), Barantolla americana Hartman, 1963 (type locality: west coast of US, Pacific Ocean, deep water, between 260–976 m); Barantolla lepte Hutchings, 1974 (type locality: east coast of Australia (Wallis Lake), Pacific Ocean, shallow water) and Barantolla orientalis Yabe and Mawatari, 1998 (type locality: northern Japan (Hokkaido), Pacific Ocean, shallow water). Barantolla cryptogenica sp. nov. is only similar to B. lepte in lacking chaetae on neuropodia of chaetiger 1, and mainly differs from it in the shape of prostomium (small, semicircular in B. cryptogenica sp. nov. vs long, pointed, with slightly bulbous tip in B. lepte ) and body (anteriorly enlarged in B. cryptogenica sp. nov. vs thread-like in N. lepte ), and lacking eyes (10–15 subepidermal eye spots in B. lepte ).

A species of this genus (only one specimen, reported as Barantolla sp. ) was previously reported from the deep waters (1200 m) of the Mediterranean Sea (Ionian Sea) by Langeneck et al. (2017). The species mainly differs from L. cryptogenica sp. nov. in the depth preference (deep water species) and having capillary chaetae on the neuropodium of chaetiger 1.

Distribution

This species is only known from the southern coast of Turkey, where it first appeared in the region in 2015 with one or two specimens, and then became more abundant in 2018 and 2019. It was found in 52% of samples with a maximum density of 460 ind.m − 2 in SAMSWR in 2018 and in 31% of samples with a maximum density of 150 ind.m − 2 in SAMSWR in 2019. It might have been introduced to the region from an unknown locality and vector, so this species can be classified for now as likely an alien or cryptogenic species.

Figures

Figure 15. Barantolla cryptogenica sp. nov. paratype (ESFM-POL/2017-211): (a) anterior end, lateral view; (b) limbate chaetae, thorax; (c) notopodial hooks, thorax; (d) neuropodial hooks, thorax; (e) notopodial hooks, abdomen; (f) neuropodial hooks, abdomen. Scale bar: a = 0.35 mm; b = 26 µm; c– f = 55 µm.

Figure 16. Barantolla cryptogenica sp. nov. paratype (ESFM-POL/2017-211): (a) anterior end, lateral view; (b) anterior end with everted proboscis,lateral view; (c) prostomium with everted nuchal organs, dorsal view; (d) nuchal organ, dorso-lateral view; (e) lateral organ, thorax. Scale bar: a = 0.20 mm; b = 100 µm; c = 70 µm; d = 18 µm; e = 8 µm.

Figure 17. Barantolla cryptogenica sp. nov. paratype (ESFM-POL/2017-211): (a–d) neuropodial hooks, abdomen. Scale bar: a = 4 µm; b = 2 µm; c = 9 µm; d = 4 µm.

Figure 18. Barantolla cryptogenica sp. nov. paratype (ESFM-POL/2017-211): (a) anterior end with everted nuchal organ, lateral view; (b) nuchal organ; (c) notopodial hooks, thorax; (d) neuropodial hook, abdomen. Scale bar: a = 190 µm; b = 30 µm; c = 16 µm; d = 25 µm.