Leitoscoloplos olei Neal & Paterson, 2020

Neal, Lenka, Paterson, Gordon L. J., Blockley, David, Scott, Ben, Sherlock, Emma, Huque, Cate & Glover, Adrian G., 2020, Biodiversity data and new species descriptions of polychaetes from offshore waters of the Falkland Islands, an area undergoing hydrocarbon exploration, ZooKeys 938, pp. 1-86 : 1

Leitoscoloplos olei Neal & Paterson sp. nov. Figures 16 , 17 , 18 , 19

Materials.

Holotype: Sample 66MFC, 450 m, -49.2584430, -59.1251589, coll. 19/03/2012, ind. 1, NHM.2018.21756. Paratypes: Sample 1MFC, 456 m, -49.2330889, -59.1689586, coll. 18/04/2012, ind. 1, NHM.2018.21716. Sample 60MFA, 450 m, -49.2545270, -59.0494527, coll. 18/03/2012, ind. 4, NHM.2018.14528-14531. Other materials: Sample 12MFA, 453 m, -49.2500069, -59.0312639, coll. 24/04/2012, ind. 1, NHM.2018.24036. Sample 13MFC, 440 m, -49.2690658, -59.1683544, coll. 17/03/2012, ind. 1, NHM.2018.24061. Sample 15MFC, 454 m, -49.2686572, -59.1133764, coll. 16/04/2012, ind. 1, NHM.2018.24089. Sample 16MFA, 459 m, -49.2684428, -59.0858878, coll. 25/04/2012, ind. 1, NHM.2018.24100. Sample 19MFA, 443 m, -49.2870544, -59.1680519, coll. 17/04/2012, ind. 1, NHM.2018.24169. Sample 1MFB, 456 m, -49.2330889, -59.1689586, coll. 18/04/2012ind. 1, NHM.2018.24196. Sample 20MFA, 444 m, -49.2868531, -59.1405528, coll. 18/04/2012, ind. 1, NHM.2018.24204. Sample 20MFB, 451 m, -49.2868531, -59.1405528, coll. 23/04/2012, ind. 1, NHM.2018.24211. Sample 22MFB,454 m, -49.2864308, -59.0855553, coll. 23/04/2012, ind. 1, NHM.2018.24249. Sample 23MFA, 450 m, -49.2862100, -59.0580569, coll. 15/04/2012, ind. 1, NHM.2018.24266. Sample 24MFC, 453 m, -49.2859825, -59.0305592, coll. 25/04/2012, ind. 1, NHM.2018.24294. Sample 26MFC, 449 m, -49.3048414, -59.1402400, coll. 24/04/2012, ind. 1, NHM.2018.24347. Sample 27MFA, 440 m, -49.3046333, -59.1127311, coll. 19/03/2012, ind. 1, NHM.2018.24356. Sample 29MFA, 453 m, -49.3041981, -59.0577142, coll. 15/04/2012, ind. 1, NHM.2018.24397. Sample 29MFB, 452 m, -49.3041981, -59.0577142, coll. 15/04/2012, ind. 1, NHM.2018.24403. Sample 36MFC, 450 m, -49.3219581, -59.0298531, coll. 25/04/2012, ind. 1, NHM.2018.24517. Sample 37MFA, 436 m, -49.3410194, -59.1671425, coll. 15/04/2012, ind. 1, NHM.2018.24525. Sample 38MFB, 434 m, -49.3408178, -59.1396133, coll. 23/04/2012, ind. 1, NHM.2018.24549. Sample 39MFB, 436 m, -49.3406094, -59.1120844, coll. 15/04/2012, ind. 1, NHM.2018.24573. Sample 41MFA, 439 m, -49.3401736, -59.0570275, coll. 14/04/2012, ind. 1, NHM.2018.24636. Sample 41MFC, 437 m, -49.3401736, -59.0570275, coll. 14/04/2012, ind. 1, NHM.2018.24644. Sample 43MFA, 430 m, -49.3588058, -59.1392994, coll. 24/12/2012, ind. 1, NHM.2018.24676. Sample 45MFC, 434 m, -49.3583828, -59.0842219, coll. 23/04/2012, ind. 1, NHM.2018.24744. Sample 46MFB, 434 m, -49.3581611, -59.0566836, coll. 14/04/2012ind. 1, NHM.2018.24757. Sample 47MFC, 444 m, -49.3769958, -59.1665347, coll. 25/03/2012, ind. 1, NHM.2018.24780. Sample 48MFA, 425 m, -49.3767939, -59.1389856, coll. 24/04/2012, ind. 1, NHM.2018.24786. Sample 50MFA, 433 m, -49.3763706, -59.0838878, coll. 25/04/2012, ind. 1, NHM.2018.24831. Sample 50MFB, 436 m, -49.3763706, -59.0838878, coll. 25/04/2012, ind. 1, NHM.2018.24837. Sample 50MFC, 436 m, -49.3763706, -59.0838878, coll. 25/04/2012, ind. 1, NHM.2018.24844. Sample 52MFA, 426 m, -49.3947819, -59.1386711, coll. 24/04/2012, ind. 1, NHM.2018.24883. Sample 53MFB, 444 m, -49.3751330, -59.1116004, coll. 25/03/2012, ind. 1, NHM.2018.24903. Sample 53MFC, 444 m, -49.3751330, -59.1116004, coll. 25/03/2012, ind. 1, NHM.2018.24910. Sample 5MFB, 457 m, -49.2322461, -59.0590836, coll. 16/04/2012, ind. 1, NHM.2018.25034. Sample 64MFB, 447 m, -49.2455380, -59.1060962, coll. 18/03/2012, ind. 1, NHM.2018.25119. Sample 64MFC, 447 m, -49.2455380, -59.1060962, coll. 18/03/2012, ind. 1, NHM.2018.25126. Sample 69MFA, 442 m, -49.2887900, -59.1005700, coll. 19/03/2012, ind. 1, NHM.2018.25202. Sample 69MFB, 442 m, -49.2887900, -59.1005700, coll. 19/03/2012, ind. 1, NHM.2018.25207. Sample 72MFC, 432 m, -49.3416800, -59.1407685, coll. 22/03/2012, ind. 1, NHM.2018.21480. Sample 73MFA, 436 m, -49.3416430, -59.1309949, coll. 22/03/2012, ind. 1, NHM.2018.21488. Sample 75MFB, 438 m, -49.3383880, -59.1262342, coll. 22/03/2012, ind. 1, NHM.2018.21521. Sample 75MFC, 438 m, -49.3383880, -59.1262342, coll. 22/03/2012, ind. 1, NHM.2018.21525. Sample 76MFA, 434 m, -49.3513090, -59.1454613, coll. 22/03/2012, ind. 1, NHM.2018.21531. Sample 78MFB, 444 m, -49.2522230, -59.1818433, coll.17/03/2012, ind. 1, NHM.2018.21566. Sample 78MFC, 444 m, -49.2522230, Longitude -59.1818433, coll. 17/03/2012, ind. 1, NHM.2018.21571. Sample 79MFB, 446 m, -49.2488410, Longitude -59.1867771, coll. 17/03/2012, ind. 1, NHM.2018.21584. Sample 79MFC, 446 m, -49.2488410, -59.1867771, coll. 17/03/2012, ind. 1, NHM.2018.21592. Sample 80MFB, 445 m, -49.2518660, -59.1722163, coll. 17/03/2012, ind. 1, NHM.2018.21610. Sample 80MFC, 445 m, -49.2518660, -59.1722163, coll. 17/03/2012, ind. 1, NHM.2018.21619. Sample 81MFB, 444 m, -49.2618590, -59.1865357, coll. 16/03/2012, ind. 1, NHM.2018.21631. Sample 81MFC, 444 m, -49.2618590, -59.1865357, coll. 16/03/2012, ind. 1, NHM.2018.21635. Sample 82MFC, 443 m, -49.2614970, -59.1672448, coll. 16/03/2012, ind. 1, NHM.2018.21649. Sample 9MFC, 451 m, -49.2506689, -59.1136986, coll. 16/04/2012, ind. 1, NHM.2018.21701. Sample 10MFC, 460 m, -49.2504547, -59.0862200, coll. 25/04/2012, ind. 2, NHM.2018.11382-11383. Sample 11MFB, 455 m, -49.2502342, -59.0587417, coll. 15/04/2012, ind. 2, NHM.2018.11400-11401. Sample 13MFB, 440 m, -49.2690658, -59.1683544, coll. 17/03/2012, ind. 2, NHM.2018.11436-11437. Sample 15MFA, 455 m, -49.2686572, -59.1133764, coll. 16/04/2012, ind. 2, NHM.2018.11446-11447. Sample 16MFB, 459 m, -49.2684428, -59.0858878, coll. 25/04/2012, ind. 2, NHM.2018.11494-11495. Sample 18MFB, 460 m, -49.2679947, -59.0309117, coll. 24/04/2012, ind. 2, NHM.2018.11542-11543. Sample 21MFC, 445 m, -49.2866453, -59.1130539, coll. 16/04/2012, ind. 2, NHM.2018.11604-11605. Sample 23MFC, 450 m, -49.2862100, -59.0580569, coll. 15/04/2012, ind. 2, NHM.2018.11646-11647. Sample 24MFB, 453 m, -49.2859825, -59.0305592, coll. 25/04/2012, ind. 2, NHM.2018.11654-11655. Sample 28MFA, 452 m, -49.3044189, -59.0852225, coll. 23/04/2012, ind. 2, NHM.2018.11740-11741. Sample 31MFB, 442 m, -49.3230311, -59.1674461, coll. 15/04/2012, ind. 2, NHM.2018.11782-11783. Sample 32MFC, 438 m, -49.3228297, -59.1399267, coll. 24/04/2012, ind. 2, NHM.2018.11800-11801. Sample 35MFB, 450 m, -49.3221858, -59.0573711, coll. 15/04/2012, ind. 2, NHM.2018.11814-11815. Sample 37MFC, 436 m, -49.3410194, Longitude -59.1671425, coll. 15/04/2012, ind. 2, NHM.2018.11862-11863. Sample 38MFC, 434 m, -49.3408178, -59.1396133, coll. 23/04/2012, ind. 2, NHM.2018.11900-11901. Sample 3MFC, 464 m, -49.2326806, -59.1140206, coll. 16/04/2012, ind. 2, NHM.2018.11936-11937. Sample 40MFA, 450 m, -49.3403947, -59.0845558, coll. 23/04/2012, ind. 2, NHM.2018.11946-11947. Sample 42MFA, 434 m, -49.3590078, -59.1668389, coll. 14/04/2012, ind. 2, NHM.2018.11988-11989. Sample 42MFB, 433, m, -49.3590078, -59.1668389, coll. 14/04/2012, ind. 2, NHM.2018.11996-11997. Sample 43MFB, 341 m, -49.3588058, -59.1392994, coll. 24/12/2012, ind. 2, NHM.2018.12020-12021. Sample 45MFA, 434 m, -49.3583828, -59.0842219, coll. 23/04/2012, ind. 2, NHM.2018.12056-12057. Sample 49MFB, 448 m, -49.3765856, -59.1114364, coll. 25/03/2012, ind. 2, NHM.2018.12118-12119. Sample 49MFC, 448 m, -49.3765856, -59.1114364, coll. 25/03/2012, ind. 2, NHM.2018.12126-12127.Sample 51MFB, 442 m, -49.3949839, -59.1662306, coll. 25/03/2012, ind. 2, NHM.2018.12156-12157. Sample 52MFC, 423 m, -49.3947819, -59.1386711, coll. 24/04/2012, ind. 2, NHM.2018.12184-12185. Sample 54MFA, 426 m, -49.3943581, -59.0835533, coll. 25/04/2012, ind. 2, NHM.2018.12210-12211. Sample 57MFA, 450 m, -49.2419730, -59.0690656, coll. 18/03/2012, ind. 2, NHM.2018.12240-12241. Sample 57MFC, 450 m, -49.2419730, -59.0690656, coll. 18/03/2012, ind. 2, NHM.2018.12242-12243. Sample 59MFA, 448 m, -49.2545600, -59.0688839, coll. 19/03/2012, ind. 2, NHM.2018.12260-12261. Sample 61MFB, 447 m, -49.2487430, -59.1206859, coll. 18/03/2012, ind. 2, NHM.2018.12308-12309. Sample 63MFA, 448 m, -49.2457310, -59.1254934, coll. 17/03/2012, ind. 2, NHM.2018.12326-12327. Sample 63MFC, 448 m, -49.2457310, -59.1254934, coll. 17/03/2012, ind. 2, NHM.2018.12336-12337. Sample 64MFA, 447 m, -49.2455380, -59.1060962, coll. 17/03/2012, 23:30, ind. 2, NHM.2018.12344-12345. Sample 68MFC, 440 m -49.2856340, -59.0958696, coll. 19/03/2012, 07:48, ind. 2, NHM.2018.12410-12411. Sample 6MFB, 458 m, -49.2320192, -59.0316156, coll. 25/04/2012, ind. 2, NHM.2018.12438-12439. Sample 6MFC, 458 m, -49.2320192, -59.0316156, coll. 25/04/2012, ind. 2, NHM.2018.12442-12443. Sample 72MFA, 432 m, -49.3416800, -59.1407685, coll. 22/03/2012, ind. 2, NHM.2018.12478-12479. Sample 77MFA, 432 m, -49.3511630, -59.1260079, coll. 22/03/2012, ind. 2, NHM.2018.12538-12539. Sample 78MFA, 444 m, -49.2522230, -59.1818433, coll. 17/03/2012, ind. 2, NHM.2018.12554-12555. Sample 7MFB, 455 m, -49.2510775, -59.1686567, coll. 17/04/2012, ind. 2, NHM.2018.12590-12591. Sample 82MFA, 443 m, -49.2614970, -59.1672448, coll. 16/03/2012, ind. 2, NHM.2018.12642-12643. Sample 10MFA, 460 m, -49.2504547, -59.0862200, coll. 25/04/2012, ind. 3, NHM.2018.12720-12722. Sample 10MFB, 460 m, -49.2504547, -59.0862200, coll. 25/04/2012, ind. 3, NHM.2018.12726-12728. Sample 15MFB, 454 m, -49.2686572, -59.1133764, coll. 16/04/2012, ind. 3, NHM.2018.12759-12761. Sample 17MFC, 450 m, -49.2679625, -59.0563564, coll. 15/04/2012, ind. 3, NHM.2018.12807-12809. Sample 19MFC, 448 m, -49.2870544, -59.1680519, coll. 17/04/2012, ind. 3, NHM.2018.12849-12851. Sample 27MFC, 440 m, -49.3046333, -59.1127311, coll. 19/03/2012, ind. 3, NHM.2018.12993-12995. Sample 30MFA, 456 m, -49.3039703, -59.0302064, coll. 25/04/2012, ind. 3, NHM.2018.13050-13052. Sample 32MFB, 438 m, -49.3228297, -59.1399267, coll. 24/04/2012, ind. 3, NHM.2018.13074-13076. Sample 35MFC, 450 m, -49.3221858, -59.0573711, coll. 15/04/2012, ind. 3, NHM.2018.13092-13094. Sample 39MFC, 436 m, -49.3406094, -59.1120844, coll. 15/04/2012, ind. 3, NHM.2018.13161-13163. Sample 43MFC, 341 m, -49.3588058, -59.1392994, coll. 24/12/2012, ind. 3, NHM.2018.13257-13259. Sample 44MFB, 429 m, -49.3585975, -59.1117606, coll. 14/04/2012, ind. 3, NHM.2018.13269-13271. Sample 44MFC, 429 m, -49.3585975, -59.1117606, coll. 14/04/2012, ind. 3, NHM.2018.13287-13289. Sample 48MFC, 460 m, -49.3767939, -59.1389856, coll. 24/04/2012, ind. 3, NHM.2018.13326-13328.Sample 4MFB, 457 m, -49.2324667, -59.0865519, coll. 25/04/2012, ind. 3, NHM.2018.13338-13340. Sample 55MFA, 449 m, -49.2452600, -59.0641536, coll. 18/03/2012, ind. 3, NHM.2018.13398-13400. Sample 57MFB, 450 m, -49.2419730, -59.0690656, coll. 18/03/2012, ind. 3, NHM.2018.13455-13457. Sample 58MFC, 453 m, -49.2417960, -59.0496559, coll. 18/03/2012, ind. 3, NHM.2018.13470-13472. Sample 60MFC, 450 m, -49.2545270, -59.0494527, coll. 19/03/2012, ind. 3, NHM.2018.13539-13541. Sample 67MFB, 442 m, -49.2889470, -59.1102897, coll. 19/03/2012, ind. 3, NHM.2018.13620-13622. Sample 70MFA, 448 m, -49.2985060, -59.1150831, coll. 22/03/2012, ind. 3, NHM.2018.13665-13667. Sample 71MFC, 449 m, -49.2983550, -59.0956094, coll. 22/03/2012, ind. 3, NHM.2018.13707-13709. Sample 76MFB, 434 m, -49.3513090, -59.1454613, coll. 23/03/2012, ind. 3, NHM.2018.13773-13775. Sample 76MFC, 434 m, -49.3513090, -59.1454613, coll. 23/03/2012, ind. 3, NHM.2018.13776-13778. Sample 77MFB, 432 m, -49.3511630, -59.1260079, coll. 22/03/2012, ind. 3, NHM.2018.13791-13793. Sample 70MFA, 448 m, -49.2985060, -59.1150831, coll. 22/03/2012, ind. 3, NHM.2018.13665-13667. Sample 71MFC, 449 m, -49.2983550, -59.0956094, coll. 22/03/2012, ind. 3, NHM.2018.13707-13709. Sample 76MFB, 434 m, -49.3513090, -59.1454613, coll. 23/03/2012, ind. 3, NHM.2018.13773-13775. Sample 76MFC, 434 m, -49.3513090, -59.1454613, coll. 23/03/2012, ind. 3, NHM.2018.13776-13778. Sample 77MFB, 432 m, -49.3511630, -59.1260079, coll. 22/03/2012, ind. 3, NHM.2018.13791-13793. Sample 81MFA, 444 m, -49.2618590, -59.1865357, coll. 16/03/2012, ind. 3, NHM.2018.13866-13868. Sample 8MFC, 459 m, -49.2508764, -59.1411775, coll. 24/04/2012, ind. 3, NHM.2018.13902-13904. Sample 90MFC, 440 m, -49.3626660, -59.1204879, coll. 25/03/2012, ind. 3, NHM.2018.13917-13919. Sample 9MFB, 451 m, -49.2506689, -59.1136986, coll. 16/04/2012, ind. 3, NHM.2018.13926-13928. Sample 11MFA, 460 m, -49.2502342, -59.0587417, coll. 15/04/2012, ind. 4, NHM.2018.13968-13971. Sample 17MFB, 450 m, -49.2679625, -59.0563564, coll. 15/04/2012, ind. 4, NHM.2018.14016-14019. Sample 21MFB, 445 m, -49.2866453, -59.1130539, coll. 16/04/2012, ind. 4, NHM.2018.14052-14055. Sample 35MFA, 450 m, -49.3221858, -59.0573711, coll. 15/04/2012, ind. 4, NHM.2018.14208-14211. Sample 45MFB, 434 m, -49.3583828, -59.0842219, coll. 23/04/2012, ind. 4, NHM.2018.14360-14363. Sample 54MFC, 426 m, -49.3943581, -59.0835533, coll. 25/04/2012, ind. 4, NHM.2018.14452-14455. Sample 56MFB, 450 m, -49.2451170, -59.0544011, coll. 18/03/2012, ind. 4, NHM.2018.14480-14483. Sample 56MFC, 450 m, -49.2451170, Longitude -59.0544011, coll. 18/03/2012, ind. 4, NHM.2018.14484-14487. Sample 59MFB, 448 m, -49.2545600, -59.0688839, coll. 19/03/2012, ind. 4, NHM.2018.14516-14519. Sample 66MFA, 445 m, -49.2583220, -59.1058241, coll.18/03/2012, ind. 4, NHM.2018.14596-14599. Sample 70MFC, 446 m, -49.2985060, -59.1150831, coll. 22/03/2012, ind. 4, NHM.2018.14684-14687. Sample 73MFB, 436 m, -49.3416430, -59.1309949, coll. 22/03/2012, ind. 4, NHM.2018.14708-14711. Sample 74MFB, 438 m, -49.3385320, -59.1456000, coll. 22/03/2012, ind. 4, NHM.2018.14744-14747. Sample 79MFA, 446 m, -49.2488410, -59.1867771, coll. 17/03/2012, ind. 4, NHM.2018.14816-14819. Sample 82MFB, 443 m, -49.2614970, -59.1672448, coll. 16/03/2012, ind. 4, NHM.2018.14860-14863. Sample 18MFA, 460 m, -49.2679947, -59.0309117, coll. 24/04/2012, ind. 5, NHM.2018.14954-14958. Sample 36MFA, 452 m, -49.3219581, -59.0298531, coll. 25/04/2012, ind. 5, NHM.2018.15074-15078. Sample 51MFC, 442 m, -49.3949839, -59.1662306, coll. 25/03/2012, ind. 5, NHM.2018.15239-15243. Sample 54MFB, 426 m, -49.3943581, -59.0835533, coll. 25/04/2012, ind. 5, NHM.2018.15259-15263. Sample 59MFC, 448 m, -49.2545600, -59.0688839, coll. 19/03/2012, ind. 5, NHM.2018.15299-15303. Sample 65MFA, 446 m, -49.2584430, -59.1251589, coll. 18/03/2012, ind. 5, NHM.2018.15354-15358. Sample 65MFB, 446 m, -49.2584430, -59.1251589, coll. 18/03/2012, ind. 5, NHM.2018.15364-15368. Sample 90MFB, 440 m, -49.3626660, -59.1204879, coll. 25/03/2012, ind. 5, NHM.2018.15589-15593. Sample 36MFB, 450 m, -49.3219581, -59.0298531, coll. 25/04/2012, ind. 6, NHM.2018.15797-15802. Sample 46MFA, 434 m, -49.3581611, -59.0566836, coll. 14/04/2012, ind. 6, NHM.2018.15839-15844. Sample 58MFB, 453 m, -49.2417960, -59.0496559, coll. 18/03/2012, ind. 6, NHM.2018.15923-15928. Sample 75MFA, 438 m, -49.3383880, -59.1262342, coll. 22/03/2012, ind. 6, NHM.2018.16121-16126. Sample 77MFC, 432 m, -49.3511630, -59.1260079, coll. 22/03/2012, ind. 6, NHM.2018.16139-16144. Sample 16MFC, 459 m, -49.2684428, -59.0858878, coll. 25/04/2012, ind. 7, NHM.2018.16226-16232. Sample 22MFA, 454 m, -49.2864308, -59.0855553, coll. 23/04/2012, ind. 7, NHM.2018.16261-16267. Sample 22MFC, 454 m, -49.2864308, -59.0855553, coll. 23/04/2012, ind. 7, NHM.2018.16275-16281. Sample 28MFB, 451 m, -49.3044189, -59.0852225, coll. 23/04/2012, ind. 7, NHM.2018.16303-16309. Sample 28MFC, 451 m, -49.3044189, -59.0852225, coll. 23/04/2012, ind. 7, NHM.2018.16310-16316. Sample 2MFB, 456 m, -49.2328881, -59.1414894, coll. 24/04/2012, ind. 7, NHM.2018.16317-16323. Sample 55MFB, 449 m, -49.2452600, -59.0641536, coll. 18/03/2012, ind. 7, NHM.2018.16520-16526. Sample 55MFC, 449 m, -49.2452600, -59.0641536, coll. 18/03/2012, ind. 7, NHM.2018.16527-16533. Sample 44MFA, 432 m, -49.3585975, -59.1117606, coll. 14/04/2012, ind. 8, NHM.2018.16984-16991. Sample 73MFC, 436 m, -49.3416430, -59.1309949, coll. 22/03/2012, ind. 8, NHM.2018.17136-17143. Sample 18MFC, 460, -49.2679947, -59.0309117, coll. 24/04/2012, ind. 10, NHM.2018.17581-17590.

Description.

Holotype (NHM.2018.21756) incomplete, 9 mm long and 0.7 mm wide for 39 chaetigers; paratypes (NHM.2018.21716 and NHM.2018.14528-31), all incomplete specimens, 6-9 mm long and 0.6-0.8 mm wide for 36-45 chaetigers; body cylindrical (Figs 16a ; 19a ), narrowing posteriorly. Colour in alcohol pale yellow (Fig. 19a ).

Prostomium short, conical, anteriorly pointed (Fig. 16b ). Peristomium broad, achaetous, anteriorly bearing a pair of small nuchal organs; eyes absent.

Thorax with 9 chaetigers; notopodial and neuropodial postchaetal lobes very short, knob-like in chaetiger 1-2; notochaetal postchaetal lobes on chaetigers 3-9 initially digitate then becoming long and slender (Figs 16e ; 17a ); neuropodial postchaetal lobeson chaetigers 3-9 similar to notopodial lobes, but approaching mammiform shape in chaetigers 7-9; no subpodal or ventral papillae.

Abdomen from chaetiger 10 (Fig. 16e ); abdominal notopodial postchaetal lobes resemble those of thorax but thinner and longer; abdominal neuropodial postchaetal lobes robust, cylindrical, distally bilobed with both lobes short and blunt, but outer lobe narrower (Figs 16c, d ; 17b, d ); subpodal flange moderately developed (Figs 16c ; 17b ); subpodal papillae and interramal cirri absent.

Branchiae from chaetiger 17 or 18 (mostly 18) (Fig. 16f ), initially small and triangular, increasing progressively in size, becoming large, strap-like, asymmetrical with distal tip blunt and curved medially, in posterior chaetigers assuming "spear-head like" shape (Figs 16d, g ; 17d ); posterior branchiae longest, up to twice length of notopodial postchaetal lobes.

All thoracic chaetae camerated capillaries (Fig. 18a, b ); in thoracic notopodia few chaetae present (10-20, size dependent), arranged in a single row; in thoracic neuropodia chaetae numerous, arranged in two rows. Abdominal notochaetae include camerated capillaries (Fig. 18b ) and forked chaetae, with unequal tynes (Fig. 18c, d ), two per fascicle observed; abdominal neurochaetae as long, weakly camerated capillaries only (Fig. 18e ). Pygidium not observed.

Remarks.

Currently, twelve species of Leitoscoloplos are known from the Magellanic province and the Southern Ocean (see Table 2 ) thanks to revisionary work of Mackie (1987) and more recently Blake (2017). The genus Leitoscoloplos became species rich in the southern waters, as previous reports of L. kerguelensis (Fig. 19b ) were re-examined.

Leitoscoloplos olei sp. nov. is very similar to L. plataensis Blake, 2017 recorded off Uruguay and Argentina, in the intertidal to 144 m depths in coarse sediments. Both species are small and slender, sharing similar form of prostomium, thoracicand abdominal postchaetal lobes (both noto- and neuropodial) and having asymmetrical branchiae, which Blake (2017) describes as having lateral lobe. The main difference is the start of branchiae, which is in chaetigers 13-16 in L. plataensis , but 17-18 (mostly 18) in L. olei sp. nov. from Falkland Islands. Additional differences are more subtle. Blake (2017) commented that furcate chaetae are only rarely found in L. plataensis , but these are commonly encountered in abdominal notopodia of L. olei sp. nov., numbering two per fascicle. The two species also differ in bathymetric distribution, which is shallower in L. plataensis (intertidal to 144 m), but deeper in L. olei sp. nov. (ca. 450 m).

For full comparison of Leitoscoloplos species known from the area see Table 2 , as well as discussion in Mackie (1987) and Blake (2017).

Etymology.

Specific name olei is genitive case of oleum, which is Latin for oil, to acknowledge the discovery of this species during the oil exploration activities.

Distribution.

This species is only known from its type locality, North Falklands Basin, at ca. 450 m depth.

Figures

Figure 16. Leitoscoloplos olei sp. nov., paratype (NHM. 2018.21716) Shirla-stained a specimen in lateral view b detail of prostomium c detail of abdominal chaetiger showing subpodal flange d detail of abdominal chaetiger showing branchia (br), notopodial (ntl) and bilobed neuropodial lobes (nrl) e detail of transition between thoracic and abdominal segments in lateral view (the last thoracic and first abdominal segment highlighted with arrows) f detail of transition to branchiate region in dorsal view (first occurrence of branchiae highlighted with arrow) g detail of posterior abdominal segments. Scale bars: 500 µm (a); 200 µm (b, c); 80 µm (d); 250 µm (e); 300 µm (f); 150 µm (g).

Figure 17. Parapodial sequence of Leitoscoloplos olei sp. nov., paratype (NHM. 2018.21716) a thoracic chaetiger (chaetiger 6) b pre-branchiate abdominal chaetiger c branchiate abdominal chaetiger d posterior branchiate abdominal chaetiger. Scale bars: 1 mm.

Figure 18. Leitoscoloplos olei sp. nov., holotype (NHM. 2018.21756) a thoracic camerated notochaetae b thoracic camerated neurochaetae c bundle of neurochaetae, including the camerated capillaries and furcate chaetae d detail of furcate chaetae e abdominal camerated capillaries. Scale bars: 100 µm (a-c, e); 25 µm (d).

Figure 19. Comparison of Leitoscoloplos olei sp. nov. and L. kerguelensis a L. olei sp. nov., holotype (NHM. 2018.21756) in lateral view b comparison of L. olei sp. nov. and one of the syntypes (BMNH. ZK. 1885.12.1.252) of L. kerguelensis, both specimens in lateral view. Scale bars: 1 mm.