Phormosoma bursarium A. Agassiz, 1881

Anderson, Owen F., 2016, A review of New Zealand and southeast Australian echinothurioids (Echinodermata: Echinothurioida) — excluding the subfamily Echinothuriinae — with a description of a new species of Tromikosoma, Zootaxa 4092 (4), pp. 451-488 : 480-484

Phormosoma bursarium A. Agassiz, 1881

( Figures 26–27 )

Material examined. 1006 specimens from 216 records (NIWA, Te Papa, MV, AM).

Lord Howe Rise: 1 specimen, 32° 26.7´S, 161° 46.9´E, 1130–1147 m, MV F167643; 1 specimen, 32° 41.8´S, 162° 33.5´E, 855–874 m, MV [TAN0308/079]; 2 specimens, 32° 42.5´S, 162° 33.9´E, 850–872 m, MV F167676; 1 specimen, 34° 12.4´S, 163° 17.2´E, 1076–1083 m, MV [TAN0308/91]. West Norfolk Ridge: 6 specimen, 33° 49.5´S, 166° 58.8´E, 950–987 m, MV F167641. Norfolk Ridge: 2 specimens, 30° 10.7´S, 167° 44.2´E, 952 m, NIWA45067; 3 specimens, 29° 53.4´S, 167° 48.4´E, 653–656 m, MV [TAN0308/018]. Louisville Ridge: 1 specimen, 42° 53´S, 162° 25 W, EC5863 (dry). Northern North Island: 4 specimens, 35° 6´S, 172° 24´E, EC1725 (dry); 2 specimens, 35° 6´S, 172° 24´E, EC 1725 (dry); 2 specimens, 36° 0´S, 172° 52´E, 999 m, NIWA45124; 2 specimens, 36° 3.4´S, 173° 10.7´E, 929– 845 m, NIWA45093; 2 specimens, 36° 6.7´S, 173° 15.6´E, 848– 848 m, NIWA29474; 1 specimen, 36° 6´S, 173° 16´E, 850– 850 m, NIWA29475; 1 specimen, 36° 28.7´S, 173° 43.8´E, EC5878 (dry); 2 specimens, 34° 40.6´S, 173° 50.5´E, NIWA45065; 1 specimen, 37° 6.6´S, 173° 54.1´E, EC5875 (dry); 11 specimens, 37° 28.5´S, 173° 58.6´E, EC3979 (dry); 4 specimens, 37° 18.1´S, 173° 59´E, EC3959; 6 specimens, 34° 39´S, 174° 4.2´E, NIWA45078; 1 specimen, 35° 0´S, 174° 24´E, EC5018 (dry); 3 specimens, 35° 0.6´S, 174° 40.1´E, 560 m, NIWA45052; 1 specimen, 35° 0.2´S, 174° 49.2´E, 625 m, NIWA59350; 6 specimens, 34° 59.5´S, 174° 51.9´E, EC5865 (dry); 1 specimen, 35° 8´S, 175° 8.5´E, 794 m, NIWA29518; 1 specimen, 35° 0´S, 175° 13´E, 575 m, NIWA45088; 2 specimens, 36° 38.8´S, 176° 11´E, 288 m, NIWA29517. Bay of Plenty: 1 specimen, 37° 0.7´S, 176° 14.1´E, 289–291 m, NIWA29470; 7 specimens, 36° 40.9´S, 176° 14.8´E, 465 m, NIWA45038; 8 specimens, 36° 42.2´S, 176° 15.9´E, 520 m, NIWA45033; 5 specimens, 36° 52.5´S, 176° 16.1´E, 307 m, NIWA45037; 4 specimens, 37° 3´S, 176° 17´E, EC 1058; 2 specimens, 37° 6´S, 176° 18´E, EC4134; 2 specimens, 36° 48.1´S, 176° 18.1´E, 522 m, NIWA45057; 8 specimens, 37° 31´S, 176° 18.5´E, EC4133; 5 specimens, 37° 8´S, 176° 18.9´E, EC5856 (dry); 1 specimen, 36° 51.8´S, 176° 18.9´E, 509–512 m, NIWA29473; 2 specimens, 36° 51.8´S, 176° 18.9´E, 509–512 m, NIWA45070; 1 specimen, 36° 40.5´S, 176° 19.2´E, 909 m, NIWA45086; 15 specimens, 36° 57.8´S, 176° 19.3´E, 535 m, NIWA29519; 4 specimens, 37° 1.2´S, 176° 19.5´E, 567–568 m, NIWA29516; 9 specimens, 36° 54.8´S, 176° 20.4´E, 588 m, NIWA45035; 6 specimens, 37° 9.9´S, 176° 21.7´E, 518 m, NIWA29508; 2 specimens, 36° 21.6´S, 176° 23.4´E, 995 m, NIWA45127; 2 specimens, 37° 4.3´S, 176° 26.6´E, EC5870 (dry); 3 specimens, 37° 10.6´S, 176° 26.6´E, EC5868 (dry); 3 specimens, 36° 30.3´S, 176° 30.5´E, 990 m, NIWA45117; 31 specimens, 37° 23.2´S, 176° 32.9´E, 525 m, NIWA29484; 30 specimens, 37° 32.3´S, 176° 36.3´E, 251 m, NIWA29505; 8 specimens, 37° 32.3´S, 176° 36.3´E, 251 m, NIWA29512; 1 specimen, 37° 10.8´S, 176° 38.3´E, EC5858 (dry); 1 specimen, 37° 10.8´S, 176° 38.3´E, EC5867 (dry); 20 specimens, 37° 27.8´S, 176° 39.7´E, 523 m, NIWA29506; 2 specimens, 37° 27.8´S, 176° 39.7´E, 523 m, NIWA29521; 3 specimens, 37° 22´S, 176° 40´E, EC5859 (dry); 30 specimens, 37° 29.7´S, 176° 40.4´E, 460 m, NIWA29503; 10 specimens, 37° 23.5´S, 176° 45´E, EC5855 (dry); 27 specimens, 37° 31.7´S, 176° 47´E, 570 m, NIWA29485; 12 specimens, 37° 31.7´S, 176° 47´E, 570 m, NIWA29504; 30 specimens, 37° 32.5´S, 176° 48.6´E, 550 m, NIWA29486; 20 specimens, 37° 32.5´S, 176° 48.6´E, 550 m, NIWA29487; 21 specimens, 37° 32.5´S, 176° 48.6´E, 550 m, NIWA29502; 27 specimens, 37° 32.5´S, 176° 48.6´E, 550 m, NIWA45048; 1 specimen, 37° 18.7´S, 177° 3.9´E, 725– 550 m, NIWA6609; 1 specimen, 37° 23.9´S, 177° 6.9´E, EC5852 (dry); 1 specimen, 37° 33´S, 177° 18´E, EC1061; 1 specimen, 37° 33´S, 177° 18´E, EC 1727 (dry); 2 specimens, 37° 32.3´S, 177° 30.1´E, EC2718 (dry); 7 specimens, 37° 29.7´S, 177° 32´E, EC3960; 1 specimen, 37° 24.7´S, 178° 0.2´E, 503 m, NIWA45064; 2 specimens, 37° 46´S, 178° 57´E, EC4097. East coast North Island: 15 specimens, 41° 4.7´S, 176° 23´E, 446 m, NIWA29468; 1 specimen, 40° 38.6´S, 176° 57.4´E, 638–711 m, NIWA76740; 1 specimen, 40° 46.1´S, 176° 59.6´E, EC3896 (dry); 6 specimens, 39° 18.3´S, 178° 11.3´E, EC5857 (dry); 1 specimen, 39° 18.8´S, 178° 13.8´E, 490 m, NIWA45056; 3 specimens, 39° 28.2´S, 178° 24.8´E, 865– 865 m, NIWA29520. Cook Strait: 1 specimen, 41° 56.7´S, 174° 37´E, 964– 1005 m, NIWA63820; 8 specimens, 41° 59.1´S, 174° 41.9´E, 730– 685 m, NIWA64104; 3 specimens, 41° 55.9´S, 174° 43.2´E, EC5854 (dry); 2 specimens, 41° 53.8´S, 174° 55.6´E, 913–948 m, NIWA64230; 1 specimen, 41° 42´S, 175° 15´E, EC5866 (dry); 1 specimen, 41° 31.2´S, 175° 48.4´E, 746– 723 m, NIWA63453; 1 specimen, 41° 33.3´S, 175° 49.6´E, 917–945 m, NIWA63410; 1 specimen, 41° 27.7´S, 175° 53.8´E, 960– 923 m, NIWA63553; 1 specimen, 41° 24.6´S, 175° 53.9´E, 614–670 m, NIWA63593; 1 specimen, 41° 20.2´S, 176° 10.9´E, 730– 687 m, NIWA63706; 1 specimen, 41° 21.8´S, 176° 12´E, 998– 987 m, NIWA70991. Chatham Rise: 1 specimen, 43° 2´S, 174° 59´E, EC2666 (dry); 14 specimens, 43° 2´S, 174° 59´E, EC 2717 (dry); 4 specimens, 42° 57.9´S, 175° 27.8´E, EC3968; 3 specimens, 43° 10´S, 175° 44´E, EC7440 (dry); 1 specimen, 44° 20´S, 175° 46´E, 620–710 m, NIWA49658; 1 specimen, 42° 38.2´S, 176° 10.5´E, EC5869 (dry); 1 specimen, 43° 50.4´S, 176° 42.4´E, 479– 479 m, NIWA33530; 2 specimens, 43° 50.4´S, 176° 42.4´E, 479– 479 m, NIWA33533; 5 specimens, 43° 48´S, 177° 32.3´E, EC1726 (dry); 1 specimen, 43° 48´S, 177° 39.8´E, EC 1730 (dry); 1 specimen, 43° 40.4´S, 177° 50.5´E, EC1728 (dry); 1 specimen, 43° 40.4´S, 177° 50.5´E, EC 1731 (dry); 1 specimen, 42° 46.6´S, 178° 14.5´E, 957– 953 m, NIWA58246; 42 specimens, 44° 4.7´S, 178° 15.3´E, 935 m, NIWA29494; 10 specimens, 44° 9.4´S, 178° 46.8´E, 922 m, NIWA29477; 6 specimens, 44° 9.8´S, 178° 50.5´E, 957 m, NIWA29511; 1 specimen, 43° 51´S, 178° 55.1´E, 485 m, NIWA29493; 3 specimens, 42° 59.6´S, 178° 59.9´E, 534–539 m, NIWA41426; 2 specimens, 43° 48´S, 179° 0´E, 431 m, NIWA23723; 3 specimens, 44° 12.4´S, 179° 3.6´E, 959 m, NIWA29476; 7 specimens, 44° 12.4´S, 179° 3.6´E, 959 m, NIWA29500; 1 specimen, 44° 8.8´S, 179° 5.5´E, 854 m, NIWA29478; 1 specimen, 43° 22.2´S, 179° 11.1´E, 414– 414 m, NIWA65164; 1 specimen, 43° 58.8´S, 179° 37.9´E, 531–532 m, NIWA33547; 1 specimen, 44° 15.7´S, 179° 53.7´E, 912 m, NIWA45116; 1 specimen, 43° 22´S, 179° 56´E, 455 m, NIWA60080; 1 specimen, 43° 50.1´S, 179° 0.1´W, 405 m, NIWA29515; 1 specimen, 44° 15´S, 178° 59.9´W, 540 m, NIWA45090; 14 specimens, 44° 8.5´S, 178° 37.8´W, 482–483 m, NIWA29483; 1 specimen, 43° 37.7´S, 178° 36.6´W, 420–426 m, NIWA33590; 10 specimens, 43° 50.5´S, 178° 35.4´W, 460–462 m, NIWA33586; 3 specimens, 44° 6.4´S, 178° 33´W, 459–460 m, NIWA33550; 17 specimens, 44° 4.1´S, 178° 33´W, 451–452 m, NIWA33582; 1 specimen, 44° 18.9´S, 178° 14.2´W, 665 m, NIWA29514; 2 specimens, 44° 4.8´S, 177° 58.3´W, 474–479 m, NIWA33561; 5 specimens, 42° 59.9´S, 177° 36´W, 520–525 m, NIWA33578; 1 specimen, 44° 41.4´S, 177° 30.1´W, 1174 m, NIWA29471; 1 specimen, 44° 18´S, 176° 50´W, 243– 173 m, EC5853 (dry); 2 specimens, 43° 1.3´S, 176° 6.9´W, 666 m, NIWA45087; 1 specimen, 42° 55.9´S, 175° 34.7´W, 905 m, NIWA45069; 2 specimens, 43° 17.4´S, 175° 33.7´W, 638–644 m, NIWA33566. East coast South Island: 1 specimen, 42° 37.2´S, 173° 42´E, EC5861 (dry); 1 specimen, 42° 55´S, 173° 43´E, EC9360; 1 specimen, 42° 40´S, 173° 44.6´E, 750 m, NIWA45042; 2 specimens, 43° 14´S, 173° 52´E, 552–567 m, NIWA62821; 3 specimens, 44° 5´S, 174° 8.6´E, 555 m, NIWA45098; 1 specimen, 43° 59.8´S, 174° 19.2´E, 565 m, NIWA45081; 1 specimen, 42° 1.8´S, 174° 26.5´E, 885 m, NIWA45058; 1 specimen, 45° 25´S, 174° 30´E, 1233 m, NIWA29460; 2 specimens, 44° 2´S, 174° 46.6´E, 500 m, NIWA19013; 30 specimens, 44° 2´S, 174° 46.6´E, 500 m, NIWA45106; 25 specimens, 44° 2´S, 174° 46.6´E, 500 m, NIWA45108; 1 specimen, 44° 7.9´S, 174° 50.7´E, 516–518 m, NIWA33522; 1 specimen, 44° 7.9´S, 174° 50.7´E, 516–518 m, NIWA41223. Southern South Island: 4 specimens, 46° 29.3´S, 166° 25.6´E, 562 m, NIWA29472; 1 specimen, 46° 47.8´S, 166° 56.2´E, 800 m, NIWA45063; 2 specimens, 47° 7´S, 168° 9´E, NIWA45099; 1 specimen, 47° 9.8´S, 169° 28.4´E, EC1729 (dry); 4 specimens, 47° 27.2´S, 169° 58.9´E, 941–951 m, NIWA66711; 1 specimen, 46° 38.5´S, 170° 59´E, 1275 m, NIWA45120; 1 specimen, 46° 10´S, 171° 0.2´E, 731 m, NIWA45060. West coast South Island: 1 specimen, 42° 43´S, 168° 42´E, 1256 m, NIWA34852; 7 specimens, 43° 22.5´S, 169° 17´E, 478 m, NIWA45066; 5 specimens, 42° 24.3´S, 169° 25´E, 1047 m, NIWA45122; 8 specimens, 43° 4.9´S, 169° 25.4´E, 729– 678 m, NIWA29469; 1 specimen, 42° 43´S, 169° 45´E, 731 m, NIWA45100; 3 specimens, 42° 47.2´S, 169° 51.7´E, 768 m, NIWA45031; 2 specimens, 42° 43´S, 169° 52´E, 469 m, NIWA45102; 4 specimens, 42° 39.3´S, 170° 0.7´E, 420 m, NIWA45059; 12 specimens, 42° 36.8´S, 170° 3.3´E, EC5860 (dry); 2 specimens, 42° 31´S, 170° 10´E, 836 m, NIWA45101; 10 specimens, 42° 0´S, 170° 16´E, 748 m, NIWA45053; 3 specimens, 41° 58.5´S, 170° 24.5´E, EC4226; 5 specimens, 42° 35.9´S, 170° 39.7´E, 201 m, NIWA45096. Bounty Plateau: 1 specimen, 47° 59.3´S, 179° 30.4´W, 493 m, NIWA45084. Campbell Plateau: 2 specimens, 51° 59´S, 167° 45.2´E, 763– 754 m, NIWA66706; 3 specimens, 50° 14.4´S, 168° 54.7´E, 586–587 m, NIWA66705; 1 specimen, 49° 53.4´S, 169° 29´E, 635–644 m, NIWA66704; 4 specimens, 50° 22.7´S, 169° 34.2´E, 600–602 m, NIWA61625; 1 specimen, 49° 30´S, 169° 59.8´E, 638 m, NIWA45072; 1 specimen, 49° 50´S, 170° 13´E, 611 m, NIWA29492; 3 specimens, 49° 50´S, 170° 13´E, 611 m, NIWA45041; 1 specimen, 49° 49.7´S, 170° 13.9´E, 600 m, NIWA45079; 1 specimen, 49° 50´S, 170° 14´E, 593 m, NIWA29479; 3 specimens, 49° 50´S, 170° 14´E, 593 m, NIWA45097; 4 specimens, 49° 0.8´S, 170° 24.6´E, 730 m, NIWA45112; 1 specimen, 48° 40´S, 170° 48.5´E, 814m, NIWA29434; 6 specimens, 48° 58´S, 171° 4´E, EC5871 (dry); 6 specimens, 48° 45´S, 172° 0´E, 658 m, NIWA45054; 2 specimens, 50° 34´S, 173° 40.3´E, 679– 674 m, NIWA66708; 1 specimen, 50° 25.5´S, 173° 44.4´E, 692 m, NIWA45076; 1 specimen, 51° 1.3´S, 173° 49.5´E, 748– 717 m, NIWA46086; 5 specimens, 51° 1.3´S, 173° 49.5´E, 748– 717 m, NIWA46087; 4 specimens, 50° 58´S, 173° 57´E, 832 m, NIWA29430; 1 specimen, 49° 48´S, 176° 1´E, 1256 m, NIWA45126. Challenger Plateau: 1 specimen, 38° 34.9´S, 167° 8.9´E, 974– 974 m, NIWA41280; 2 specimens, 37° 37.2´S, 167° 23.1´E, 1012 –1014 m, NIWA33633; 1 specimen, 37° 37.2´S, 167° 23.1´E, 1012–1014 m, NIWA33634; 3 specimens, 40° 46´S, 167° 54.9´E, EC5879 (dry); 1 specimen, 39° 43´S, 167° 56´E, 792 m, NIWA45085; 17 specimens, 37° 45.4´S, 168° 12.9´E, 700–702 m, NIWA33631; 3 specimens, 40° 50.1´S, 168° 14.8´E, EC5862 (dry); 2 specimens, 40° 50.1´S, 168° 14.8´E, 1009 m, NIWA45043; 1 specimen, 37° 44.3´S, 169° 18.7´E, 691–705 m, NIWA33630; 6 specimens, 39° 27.5´S, 169° 36.5´E, EC9366; 1 specimen, 39° 32.6´S, 169° 42.9´E, 634–636 m, NIWA33643; 1 specimen, 39° 32.6´S, 169° 42.9´E, 634–636 m, NIWA33644; 1 specimen, 39° 32.6´S, 169° 42.9´E, 634–635 m, NIWA33645; 4 specimens, 39° 41.5´S, 169° 46´E, EC9367; 9 specimens, 40° 7.6´S, 170° 12.3´E, 803–804 m, NIWA33649; 1 specimen, 40° 33.1´S, 170° 57.3´E, 570 m, NIWA45068; 3 specimens, 40° 51.5´S, 170° 58´E, EC4224; 30 specimens, 40° 23´S, 171° 6´E, EC4223; 2 specimens, 40° 23´S, 171° 6´E, EC5864 (dry); 13 specimens, 40° 39.7´S, 171° 6.8´E, 503– 497 m, NIWA45055; 1 specimen, 39° 38.2´S, 171° 37.5´E, 473–491 m, NIWA33654. Southeast Australia: 1 specimen, 39° 3.4´S, 148° 37.3´E, 444–468 m, MV F168942; 1 specimen, 39° 1.5´S, 148° 44.2´E, 1140–1160 m, MV F168941; 10 specimens, 41° 54.3´S, 148° 45.1´E, 1273 – 1190 m, MV [STN83SLOPE]; 2 specimens, 35° 45´S, 150° 30´E, EC5073 (dry); 1 specimen, 35° 45´S, 150° 30´E, EC5877 (dry); 1 specimen, 34° 3´S, 151° 12´E, EC 1231 (dry); 6 specimens, 35° 0´S, 151° 16.2´E, 1100 m, MV [no data]; 1 specimen, 33° 54´S, 151° 18´E, EC5074 (dry); 2 specimens, 29° 54´S, 153° 30´E, EC5066 (dry); 1 specimen, 29° 54´S, 153° 30´E, EC5876 (dry); 2 specimens, 33° 28.8´S, 152° 13.2´E, 1200 m, AM J24889 . South Australia: 2 specimens, 38° 42´S, 141° 0´E, 549–586 m, MV F168938. Unless stated, all stored in 80% ethanol.

Size range. up to at least 105 mm TD.

Occurrence. P. bursarium is widely distributed around New Zealand, being present on all of the major offshore bathymetric features of the region, with a conservative depth range of 243–1190 m (although only two of the New Zealand records were shallower than 500 m), and a total recorded depth range of 173– 1273 m. In Australia they are known from the northwest coast and the east coast off New South Wales (Rowe & Gates 1995) ( Figure 27 ).

The species is also widely known outside of Australasia; throughout the Indo-Pacific, in the Arabian Sea, and off South Africa (e.g. Mortensen 1935, Mironov 1971, Clark and Courtman-Stock 1976).

Remarks. The genus Phormosoma is most readily distinguished from other genera of echinothurioids by the complete covering of the oral surface by tubercles with large, sunken areoles; giving it a distinctive honeycombed appearance. Also there are no hoofs on the primary spines of the oral surface, which have instead a fleshy sac encasing the end of these more or less club-shaped spines. In fresh specimens in good condition these are sometimes very distinctive and filled with diffuse connective tissue (Emson and Young 1998), but more usually they have been punctured and compressed against the spine, making them fairly inconspicuous. A very distinctive feature of the genus are the aboral fleshy sacs encasing the aboral primary spines. These unusual and delicate sacs, almost never retained on the spines in trawl or dredge-caught specimens, were first noted in images of P. placenta taken from a submersible (Grassle et al. 1975, Gage & Tyler 1992, Emson & Young 1998).

P. bursarium was first recognised in New Zealand from specimens collected on the Chatham Rise (Fell, 1958). Subsequently they have been regularly seen in the bycatch of offshore fishing trawlers, and numerous specimens have been collected by fisheries observers and from research surveys. This is a small to medium sized species (mostly <100 mm TD), generally a light brown colour but with a slight red tinge when fresh. The teeth are slender and acutely pointed, similar to those of Sperosoma , Tromikosoma , and Kamptosoma , but distinct from Hygrosoma and all Echinothuriinae . Only tridentate and triphyllous pedicellariae are present in Phormosoma .

Considerable variability among specimens has been noted by earlier authors (Agassiz & Clark 1909, Mortensen 1935, 1940) who had some difficulty in separating the various forms into species. However, the Indo- Pacific P. bursarium stands out somewhat from the Atlantic P. placenta due to its generally larger size. Whereas P. placenta rarely grows to more than 90 mm TD the adult size of P. bursarium is 100–120 mm TD. About 50 randomly selected examples of the New Zealand specimens were measured, from several stations; about a third were greater than 90 mm TD and the largest were 100–105 mm TD. Another difference between P. placenta and P. bursarium is that the primary spines of the aboral side are more curved in the former, and the marginal spines coarser in the latter. The New Zealand specimens differ slightly in that although the marginal spines are more or less distinctly thorny, the aboral primary spines are fairly straight. Both species are well-known and relatively common. The dark red P. verticillatum , from the Indian Ocean, differs from both these species in that the aboral primary spines are adorned by whorls of spinelets, and it is smaller still—not reaching more than 60 mm TD (Mortensen 1935). The relationship of the fourth member of the genus, P. rigidum , is discussed in the next section.

Figures

FIGURE 26. Phormosoma bursarium, NIWA 63593. (95 mm TD). Left, aboral view; right, oral view.

FIGURE 27. Phormosoma bursarium. Distribution of confirmed records in New Zealand and southeast Australia, from material examined. Number of records = 216.