Amphoriscus ancora, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225: 201-204

publication ID

http://doi.org/ 10.5281/zenodo.272951

publication LSID

lsid:zoobank.org:pub:6D68A019-6F63-4AA4-A8B3-92D351F1F69B

persistent identifier

http://treatment.plazi.org/id/03A80010-779F-FF67-FF14-A68794D8FE4A

treatment provided by

Plazi

scientific name

Amphoriscus ancora
status

sp. nov.

Amphoriscus ancora  sp. nov.

Figures 128View FIGURE 128 a –d, 129a –e

Material examined. Holotype RMNH Por. 9741, Suriname, ‘Luymes’ Guyana Shelf Expedition, station 43, 6.5167°N 53.9333°W, depth 35 m, Agassiz trawl, bottom shell gravel, 28 August 1970GoogleMaps  .

Description. ( Fig. 128View FIGURE 128 a) Thin flattened oval tube, length 18 mm high, 4 mm in greatest diameter. Oscule naked, with two short root-like holdfasts. Color (in alcohol) dirty white to pale beige.

Skeleton. ( Figs 128View FIGURE 128 b –d) Inarticulate, with choanosomal skeleton made up of the apical actines of the cortical tetractines and the unpaired actines of subatrial triactines. No scattered spicules in the choanosome. In cross section ( Fig. 128View FIGURE 128 b) from ectosome to atrium, there are successively the cortical skeleton ( Fig. 128View FIGURE 128 c) consisting of the paired and unpaired actines of large tetractines, choanosomal skeleton ( Fig. 128View FIGURE 128 d) consisting of the apical actines of the cortical tetractines and the unpaired actines of the subatrial triactines, paired actines of the subatrial triactines, and the atrial skeleton consisting of small atrial tetractines, with their apical actines protruding in the atrial cavity. The root skeleton consists of a bundled mixture of thin diactines and peculiar curved anchoring triactines.

Spicules. ( Figs 129View FIGURE 129 a –e) Tetractines, triactines, anchoring triactines, diactines.

Tetractines divisible in (1) larger cortical tetractines ( Figs 129View FIGURE 129 a), with apical actines as long or longer than the basal actines, sizes: unpaired actines, 151– 216 –330 x 12 – 16.1 –21 µm, paired actines 135– 239 –320 x 8 – 15.4 –21 µm, apical actines 258– 311 –366 x 8 – 17.8 –20 µm, and (2) smaller atrial tetractines ( Figs 129View FIGURE 129 b) tending to be sagittal, with shorter apical actines, sizes: unpaired actines 42– 87 –186 x 3 – 8.6 –12 µm, paired actines 57– 99 –165 x 3 – 7.7 –11 µm, apical actines 9– 26 – 60 x 3 –5.3–15 µm.

Subatrial triactines ( Figs 129View FIGURE 129 c), in a large size range but less diverse and not readily divisible in categories, paired actines may be slightly wavy, unpaired actines 201– 367 –468 x 7 – 10.1 –12 µm, paired actines 129– 218 –324 x 7 – 8.6 –10.5 µm.

Anchoring triactines ( Figs 129View FIGURE 129 d,d1) from the roots, with characteristically curved unpaired actine and beaklike paired actines, in a large size range, unpaired actines 96– 386 –660 x 7 – 8.6 –10 µm, paired actines 18– 24.8 – 29 x 5 –6.8–9 µm.

Diactines ( Figs 129View FIGURE 129 e,e1) from the roots, long and thin, 600–1 0 17 – 1230 x 3 – 4.2 –6.5 µm.

Distribution and ecology. Guyana Shelf, gravel bottom at 35 m depth.

Etymology. Ancora  (Gr., latinized, a female noun) meaning anchor, referring to the shape and function of the beak-like root spicules.

Remarks. The new species shares its anchoring spicules with those of the Brazilian species Syculmis  synapta Haeckel, 1872  , assigned to Amphoriscus  by Borojevic et al. 2002b (p. 1178). This species is close to the new species, both geographically and morphologically. It differs by having the anchoring spicules all consisting of tetractines (the beak-like part of the spicule has three actines instead of two as in the new species), by the apparent entire lack of triactines (their subatrial position is taken up by tetractines in A. syculmis  ), and by the possession of a prominent apical fringe of long thin diactines. Despite the morphological similarity these differences merit recognition at the species level.

Further close, but more dissimilar, species are Caribbean A. amphora ( Haeckel, 1872)  (as Leucilla  ) and Venezuelan A. urna Haeckel, 1872  . The shape of A. amphora  is similar to that of the new species, but there is no report of anchoring root spicules, and like A. synapta  the subatrial spicules are tetractines, not triactines, nor are there any other triactines. The shape of A. urna  is more globular, but in other aspects of skeleton and spiculation it is similar to A. amphora  .

Other Amphoriscus  species of the region are: Floridian A. oviparus ( Haeckel, 1872)  (as Sycaltis ovipara  ) has small cortical triactines overlying the subcortical tetractines, lacking subatrial triactines (but having subatrial tetractines) and lacking root spicules. Cuban A. testiparus ( Haeckel, 1872)  (as Sycaltis testipara  ) is similar to A. oviparus  (so possesses cortical triactines and subatrial tetractines) but forms groups of tubes.

RMNH

National Museum of Natural History, Naturalis

Kingdom

Animalia

Phylum

Porifera

Class

Calcarea

Order

Leucosolenida

Family

Amphoriscidae

Genus

Amphoriscus

Loc

Amphoriscus ancora

Van, Rob W. M. 2017
2017
Loc

A. oviparus (

Haeckel 1872
1872
Loc

A. testiparus (

Haeckel 1872
1872