Latrunclava imago Kelly, Reiswig & Samaai
Creators: name: Kelly, Michelle
name: Sim-Smith, Carina
name: Stone, Robert
name: Reiswig, Toufiek Samaai Henry
name: Austin, William
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Poecilosclerida
Latrunculiidae
Latrunclava
Latrunclava imago

description: Latrunclava imago Kelly, Reiswig & Samaai gen. et sp. nov.
(Fig. 1 G, 2B, 13; Tables 7, 8, 9)
Material examined. Holotype— RBCM 150-00490-001: 25.2 km WNW of Amatignak Island, Delarof Islands, Amchitka Pass, central Aleutian Islands, 51.333° N, 179.503° W, 175 m, 3 Aug 2004, NOAA Fisheries, RV Roger Revelle, ROV Jason II Dive 102, Station 14, collected by R. Stone. Paratype— RBCM 015-00490-002: same locality data.
Type location. Amchitka Pass, central Aleutian Islands.
Distribution. Central Aleutian Islands.
Description. Spherical to sub-spherical sponge, about 5 cm high and 4 cm thick, with thin, conical oscules, around 2 mm wide at the tip, up to 7 mm high (Fig. 13 A). Sponge dark, rich brown, wrinkled and much contracted in the preserved state. Texture soft and compressible, the interior is cavernous, fibrous, and stringy.
Skeleton. A single layer of anisodiscorhabds forms a palisade in the ectosome, below which is a paratangential layer of megascleres, about 400 µm thick, becoming vertical near the pore fields. Numerous anisodiscorhabds and the occasional anisoconicorhabd are scattered between the subectosomal paratangential layer. The choanosomal architecture consists of wispy tracts of styles that form a very wide-meshed irregular reticulation. Numerous anisodiscorhabds, megascleres and the occasional anisoconicorhabd are scattered throughout the choanosome between tracts.
Spicules. Megascleres (Fig. 13 D; Table 7), anisostyles, head spined retrovertly (spines face away from head along shaft), often very slightly sinuous, 543 (453–632) × 11 (9–15) µm.
Microscleres (Fig. 13 E–I; Table 7), anisodiscorhabds, basal whorl comprises a ring of relatively large, simple spines that are sparsely acanthose and point slightly downwards. A manubrium spine present in the great majority of spicules (Fig. 13 E, G, H). Median whorl a horizontal ring of large, sparsely acanthose spines. Apical whorl a ring of obliquely upward pointing spines that are rarely acanthose. Apex absent, 42 (38–48) × 29 (24–34) µm.
Anisoconicorhabds (Fig. 13 B) in with basal whorl and manubrium of 2–3 obliquely projecting blunt spines, apical whorl and apex of spines, with an extended shaft between, covered in large spines, sometimes curved, projecting horizontally, spines and shaft are lightly acanthose. Three size categories: 1) short, squat and heavily spined (Fig. 12 B, left), 92 (60–110) × 12 (10–15) µm; 2) medium length, moderately heavily spined (Fig. 12 B, middle), 147 (120–160 × 20 (18–22) µm; 3) long, lightly spined on middle of shaft (Fig. 12 B, right), 197 (170–240) × 23 (20–29) µm.
Substrate, depth range and ecology. Grows on cobbles and boulders on shelf and upper slope habitats, at a depth of 179 m in areas experiencing moderate to high currents; sympatric with L. oparinae.
Etymology. Named for the ‘echo’ of the new genus Latrunclava in the North Pacific, first recorded from spicules from the Late Eocene in the region of Zealandia that formed the Oamaru Diatomite (imago, echo; L.).
Remarks. The discovery of sponges that contained a form of ‘sceptre’ in addition to normal anisodiscorhabds, superficially similar to those of Sceptrella regalis Schmidt, 1870, and S. insignis Topsent, 1890, came as a great surprise because Sceptrella is only known to date from the Atlantic Ocean region, including the Mediterranean and Gulf of Mexico. The anisoconicorhabd sceptres of Latrunclava imago subgen. et sp. nov. are quite different in that they are inequiended, with manubrium and basal whorl substructures that resembles those in the anisodiscorhabds of L. (Uniannulata) subgen. nov., in particular. The possession of three size categories of these anisoconicorhabds in Latrunclava imago subgen. et sp. nov. clearly differentiates this species from all other Latrunculiidae.
description: Published as part of Kelly, Michelle, Sim-Smith, Carina, Stone, Robert, Reiswig, Toufiek Samaai Henry & Austin, William, 2016, New taxa and arrangements within the family Latrunculiidae (Demospongiae, Poecilosclerida), pp. 1-48 in Zootaxa 4121 (1) on pages 34-36, DOI: 10.11646/zootaxa.4121.1.1, http://zenodo.org/record/265513