Bomba tricincta ( Hentschel, 1929 ) Hentschel, 1929

Kelly, Michelle, Sim-Smith, Carina, Stone, Robert, Reiswig, Toufiek Samaai Henry & Austin, William, 2016, New taxa and arrangements within the family Latrunculiidae (Demospongiae, Poecilosclerida), Zootaxa 4121 (1), pp. 1-48 : 31-33

Bomba tricincta ( Hentschel, 1929) comb. nov.

( Fig. 12 ; Tables 6 , 9 )

Latrunculia tricincta Hentschel, 1929: 869 , 926, Pl. 12, Fig. 3 .

Type Material. Holotype — ZMB Por 7851, Northern Norway, Station 8, 71.583° N, 26.9° E, 198 m, 3 Jul 1898, microscope slide annotated as “ Latrunculia 7851 tricincta, Hentschel MS, Olga Expedition”.

Type location. Northern Norway.

Distribution. West Spitzbergen to Northern Norway, to Russia’s far northeast Kola Peninsula (Murmanküste), north of the Arctic Circle, and bordered by the Barents Sea.

Description. Hentschel (1929: 869) stated that the specimen he examined was a teased preparation from W. Weltner which precluded information on the shape and other details. The specimen was illustrated in Table 12, Fig. 3 , stating that it was “at the natural size” (which was not given) and appears to be pedunculate with a collapsed apex and wrinkled stem ( Fig. 11 A). No information on the surface is given.

Skeleton. Hentschel (1929: 869) states that the skeleton is formed of strong, thick, bifurcating tracts about 80– 150 µm wide. Examination of small pieces of tissue on the microscope slide of the holotype reveal several large, robust tracts tapering from 100 to 350 µm wide, and 75 to 375 µm, splitting in two at the thicker end ( Fig. 12 B). Bundles of megascleres are also apparent, ranging in thickness from 50–100 µm.

Spicules. Megascleres ( Fig.12 C–E; Table 6 ), anisostyles with smooth heads, shaft slightly sinuous, 603 (580‒635) × 10 (8‒10) µm.

Microscleres (Fig. F–G; Table 6 ), anisodiscorhabds, composed of three whorls of bifurcating or trifurcating spines. Under light-microscopy the basal, median and apical whorls are sharply spinose, not blunt as in B. endeavourensis gen. et sp. nov., and all are bifurcate. The basal and median whorls appear to be orientated virtually perpendicular to the shaft whereas the apical whorl is oblique to the shaft and pointing forwards. No apex or manubrium is discernible even in the protorhabds. Development of the anisodiscorhabds is symmetrical, with spines developing straight from the shaft at both ends and in the middle (Fig. G), 46 (43‒50) × 35 (33‒38) µm.

Substrate, depth range and ecology. Fishery grounds, yellow sand with stones, 192 m ( Hentschel 1929).

Remarks. The microscope slide of Latrunculia tricincta , kindly supplied by Dr Carsten Lüter, Museum für Naturkund Berlin, is thought to hold spicules from the holotype; no preserved specimen has been found despite thorough searching. Examination of the microscleres reveals that this is also a species of Bomba gen. nov.; it has the same unusual microscleres with only basal, median and apical whorls. Hentschel (1929) noted that the possession of only three ‘girdles’ in L. tricincta distinguished it from all species of Latrunculia known at the time. The anisodiscorhabds of L. tricincta are clearly of the same general form as those of B. endeavourensis gen. et sp. nov.; they both possess three distinct whorls and lack a manubrium, subsidiary whorl and an apex. The anisodiscorhabds of B. tricincta differs from those of B. endeavourensis gen. et sp. nov., however, in the shorter length of the megascleres and the shorter length and smaller width of the anisodiscorhabds ( Table 5 and 6 ). The ornamentation of the anisodiscorhabds is also quite different, being sharply bifurcate spines in B. tricincta . No further specimens have been recorded that we know of, thus, the genus is restricted to the north-eastern Pacific Ocean and North Atlantic Ocean above Norway.

Figures

FIGURE 3. Latrunculia (Latrunculia) austini Samaai, Gibbons & Kelly, 2006: A. Holotype RBCM 982 - 62 - 1, British Columbia; B. Skookumchuck Narrows, Jervis Inlet, in situ; C. NHMUK 2008. 3. 27.3, Gulf of Alaska, 102 m, in situ; D. NHMUK 2008.3. 27.3, ibid, grid marks under preserved specimen are 1 cm 2; E. RBCM 014 - 00091 - 001, British Columbia, 384 m, in situ; F. RBCM 015 - 00479 - 001, Gulf of Alaska, 88 m, in situ; G. RBCM 015 - 00479 - 004, Gulf of Alaska, 106 m, distance between red laser dots is 10 cm; H. Ibid; I. Queen Charlotte Sound, 48.125 ° N, 125.371 ° W, 115 m, 27 May 2006, OCNMS ROPOS ROV Dive 953, in situ; J. Queen Charlotte Sound, 48.302 ° N, 124.938 ° W, 243 m, 0 1 Jun 2006, OCNMS ROPOS ROV Dive 958, in situ; K. Queen Charlotte Sound, 48.170 ° N, 125.370 ° W, 114 m, 11 Jul 2008, OCNMS ROPOS ROV Dive 1160, in situ. Fig. 3 A, 3 C, 3 D reproduced from Samaai et al. (2006, Fig. 3 H) with permission from Zootaxa (Magnolia Press), Stone et al. (2011: 145, Fig. 2) and Stone et al. (2011: 145, Fig. 1), respectively. Image credits for Fig. 3 A, B: Neil McDaniel, Fig. 3 I ‒ K: Olympic Coast National Marine Sanctuary, taken using the Canadian Scientific Submersible Facility ROPOS ROV digital still camera, Fig. 3 C, D, F, G, H: Robert Stone.

FIGURE 11. Morphology, megascleres and microscleres of Bomba endeavorensis gen. et sp. nov.: A. Holotype RBCM 014 - 00120 - 001, paratype 1 RBCM 014 - 00120 - 002, paratype 2 RBCM 014 - 00120 - 003, paratype 3 RBCM 014 - 00120 - 004, Endeavour Ridge, British Columbia, 2500 m, scale = 5 mm; B. Enlarged details of surface showing pigmentation on apices of anisodiscorhabds and large megascleres in a cross-hatched arrangement, scale = 500 µm; C. Centrally thickened anisostyle, scale = 200 µm; D. Rounded distal and granular bumps on head of anisostyle, scale = 20 µm; E. A range of anisodiscorhabds, scale = 20 µm; F. A range of protorhabds, scale = 20 µm; G. Apex of anisodiscorhabd, scale = 20 µm.

FIGURE 12. Morphology, megascleres and microscleres of Bomba tricincta (Hentschel, 1929) gen. nov., comb. nov.: A. Illustration of holotype ZMB Por 7851 from Northern Norway, 198 m (from Hentschel (1929, Pl. 12, Fig. 3); B. Large, thick tracts of megascleres, scale = 500 µm; C. Anisostyle, slightly sinuous, scale = 100 µm; D. Smooth proximal tip of anisostyle, scale = 100 µm; E. Smooth distal tip of anisostyle, scale = 100 µm; F. Range of anisodiscorhabds, scale = 50 µm; G. Range of protorhabds from earliest to later stages showing gradual development of the three whorls, scale = 50 µm. All images taken from microscope slide of holotype.

Tables

TABLE 6. Spicule dimensions (µm) of Bomba tricincta (Hentschel, 1929) gen. nov.

Specimen	Anisostyles	Anisodiscorhabds
ZMB Por 7851 Holotype	603 (580‒635) × 10 (8‒10)	46 (43‒50) × 35 (33‒38)
Hentschel (1929)	504‒616 × 9	45‒48 × 31‒34