New Species of Melinna (Melinnidae, Annelida) from the Australian Abyss with Comments on M. albicincta, M. cristata and M. elisabethae
Author
Gunton, Laetitia M.
Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney NSW 2010, Australia
Author
Zhang, William
School of Life and Environmental Sciences, University of Sydney NSW 2006, Australia
Author
Kupriyanova, Elena K.
Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney NSW 2010, Australia & Department of Biological Sciences, Macquarie University, North Ryde NSW 2109, Australia
Author
Hutchings, Pat A.
Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney NSW 2010, Australia & Department of Biological Sciences, Macquarie University, North Ryde NSW 2109, Australia
text
Records of the Australian Museum
2023
Rec. Aust. Mus.
2023-05-17
75
3
125
154
https://www.mendeley.com/catalogue/e8272d60-8e4e-39f2-8628-298931690154/
journal article
10.3853/j.2201-4349.75.2023.1803
2201-4349
10414060
B746588B-E743-4FCB-85CF-6AF186B1D22B
Melinna elisabethae
McIntosh, 1885
Figs 13–15
;
Tables 4
,
5
Melinna elisabethae
McIntosh, 1885: 438
;
1914
106–107 (in part).
For complete synonymy see
Mackie & Pleijel, 1995
.
Material examined
.
AM
W.21793,
4 specimens
, including prepared for
SEM
,
Cleveland
,
Tees Bay
,
England
(
54°36'N
1°48'W
), gravelly mud/rock,
44 m
, coll.
Analytical
&
Environmental Services
,
7 September 1984
.
Remarks
The original description by
Mackie & Pleijel (1995)
only provided line drawings, we give additional information based on light and SEM images.
Prostomium welldeveloped and divided into anterior and posterior parts, anterior part trilobed (
Fig. 15B
), posterior part raised triangular glandular with anterior margin bearing longitudinal slits (
Fig. 15B
). Buccal tentacles numerous and equal in length to the branchiae (
Fig. 13B
). Four pairs of branchiae annulated with distal surface exhibiting cilia patches (
Fig. 14A,C
). Branchiae circular in crosssection, anterior pair showing 40% of basal fusion and outer pair 20% fusion (
Figs 13B,C
,
14C
). One pair of dorsal hooks strongly curved and with pointed tips (
Figs 13B,D,E
,
14B,C
), solid without internal canal. Dorsal membrane with about 12 triangular projections on anterior margin (
Figs 13E
,
14A
). First segment achaetous (
Fig. 14A
) with crenulated ventral margin (
Fig. 15B
). Segments 2–5 with acicular neurochaetae arranged in elongated tori, progressively inserted more laterally (
Fig. 13B,C
). From segment 6 neuropodia with uncini continuing to pygidium. Notopodia present from segment 4, initially very small with short notochaetae, then progressively becoming larger, more laterally inserted and welldeveloped by segment 7 (
Figs 13D
,
14A
,
15C
) and on all subsequent ones. Notochaetae arranged in two tiers (
Fig. 14H
) with tips of longer ones curved (
Fig. 15A
) and with blades finely ornamented (
Figs 14F,H
,
15A,E
). Notopodia globular with posterior lobe longer than anterior one (
Fig. 14D,E,F
) and well separated from neuropodia (
Figs 14E
,
15C
). Thoracic neuropodia raised glandular tori slightly curved, bearing about 26 uncini (
Fig. 14E
). Thoracic uncini with a single row of four teeth with ornamentation on lateral face and becoming marked and behind anterior tooth strongly ornamented with small teeth (
Figs 14G
,
15D,F
). Abdominal rudimentary notopodia not observed as in
Mackie & Pleijel (1995)
, specimens very small and thin (
Fig. 15G
).Abdominal neuropodia welldeveloped but not elevated, anteriorly bearing four teeth arranged in a single row (
Fig. 15H,I
). Terminal anus bounded by pair of large lateral lobes and several smaller lateral ones (
Fig. 13a
) and lacking anal cirri. Methyl blue stain shows extensive ventral glandular areas (
Fig. 13F
). Tube with attached shell fragments on anterior end and rest of tube made of smaller sand grains and mud (
Fig. 13G
).