Two new species of Terebrasabella (Annelida: Sabellidae: Sabellinae) from Australia
Author
Murray, Anna
Author
Rouse, Greg W.
text
Zootaxa
2007
1434
51
68
journal article
10.5281/zenodo.175840
11317d12-cbbc-495d-a739-6c2272b28fd6
1175-5326
175840
Sabellinae
Latreille
Terebrasabella
Fitzhugh & Rouse, 1999
, emended
Terebrasabella
Fitzhugh & Rouse, 1999
: 358
–359.
Type
species:
Terebrasabella heterouncinata
Fitzhugh & Rouse, 1999
.
Diagnosis
.
Small-bodied species with eight thoracic and three abdominal chaetigers. Branchial crown with two pairs of radioles, pinnules pectinately arranged. Palmate membrane, radiolar flanges and radiolar eyes absent. Dorsal lips elongate with radiolar appendages. Ventral lips, parallel lamellae, and ventral sacs absent. Branchial skeleton present, with two rows of cells. Branchial lobes fused along dorsal midline. Ventral margins of branchial lobes with ventral basal flanges. Anterior peristomial ring indistinct; separation of anterior and posterior peristomial rings indistinguishable. Peristomial and pygidial eyespots absent. Posterior peristomial ring collar present, incised mid-dorsally and ventrally. Glandular ridge in chaetiger two absent. Thoracic notochaetae broadly-hooded capillaries (sensu
Fitzhugh 1989
), arranged in two rows, superior chaetae longer than those in inferior row. Two or three
types
of thoracic neuropodial uncini present in chaetigers 2–8. Uncini in chaetiger 2 either 2–4 long-handled uncini with small breast (= acicular), with a main fang surmounted by a series of homodont or heterodont teeth, or 1–2 acicular uncini which have a large gap between the large main fang and the semicircle of smaller distal teeth, with one pair slightly larger than the other teeth in the crest (=“palmate”sensu
Jones 1974
); uncini of chaetigers 3–6 acicular, similar to the hetero- or homodont uncini present in chaetiger 2; breast of uncini either a small swelling or moderately well-developed. Uncini in chaetigers 7–8, Z-shaped with breast and handle (= avicular), all teeth uniform in size and arranged in narrow elongate rasp-shaped rows; breast well-developed; handles of medium length. Companion chaetae present in neuropodia of chaetigers 2–6, absent in chaetigers 7-8. Abdominal notopodial uncini in chaetigers 9–11 acicular, either with distinct main fang surmounted by series of hetero- or homodont teeth, or a similar smaller version of the “palmate” uncinus of chaetiger 2; breast poorly- to well-developed. Abdominal neurochaetae narrowly-hooded capillaries. Simultaneous hermaphrodites; direct-developing young brooded in burrow.
Remarks.
This diagnosis is slightly altered from that of
Fitzhugh and Rouse (1999)
.
Fitzhugh (2003)
argued for a reinterpretation of the dorsal lips of sabellids and that
Terebrasabella
has radiolar appendages. This is accepted here. Also, after examination of
T. heterouncinata
specimens we must conclude that the description of the superior thoracic capillary chaetae as “narrowly-hooded” in
Fitzhugh & Rouse (1999)
, (
Figs 6
A,B), is not an accurate reflection of the shape, as all thoracic capillary notochaetae appear to have distinct ‘bilateral’ swelling of the hood, arising either side above the handle, the more elongate superior ones as well as the shorter inferior chaetae. Specimens of
T. hutchingsae
sp. nov.
, and
T. fitzhughi
sp. nov.
, also possess the same chaetae. This is seen particularly well under SEM examination (see
Fig. 3
C). We propose that these chaetae are more accurately described as “broadly-hooded” (sensu
Fitzhugh, 1989
, Fig, 22E,F). The variability of shape in the uncini of chaetiger two across the three
Terebrasabella
spp. is reflected in the diagnosis.