Revision of Leocrates Kinberg, 1866 and Leocratides Ehlers, 1908 (Annelida, Errantia, Hesionidae)
Author
Salazar-Vallejo, Sergio I.
text
Zootaxa
2020
2020-02-18
4739
1
1
114
journal article
23993
10.11646/zootaxa.4739.1.1
d3e60fb6-636b-4e03-b55a-0e910f9a468e
1175-5326
3672547
544B9C82-BF33-4EA1-9411-E1A307137466
Leocrates giardi
Gravier, 1900
Figs 29
,
30
Leocrates giardi
Gravier, 1900: 180–185
, Textfigs. 46–52, Pl. 10,
Figs 17–19
).
Leocrates claparedii
:
Fauvel 1919: 371
;
Fauvel, 1933: 44-45
(
non
Costa
in
Claparède, 1868
).
Leocrates diplognathus
:
Fauvel 1955
a: 105
(
non
Monro, 1926
).
Type material
.
Red Sea, Gulf of Aden
. Six
syntypes
(
MNHN
289), some collected in Aden (
12°46’25” N
,
46°01’35” E
) by Dr. Jousseaume in 1893, others in
Djibouti
(
11°36’ N
,
43°09’ E
),
Djibouti
, by Drs Jousseaume and Coutière in 1897, kept in the same container; no further data.
Additional material. Red Sea. Gulf of Suez.
One specimen (
MNHN
A419), no further data [
20 mm
long,
3 mm
wide].
Saudi Arabia
. Two specimens (
MNHN
A71), Mission Bonin-Perez, Côtes d’Arabie, Sta. 48, 1901, no further data [
11–13 mm
long,
2 mm
wide]. Two specimens (
MNHN
A71b), Mission Bonin-Perez, Côtes d’Arabie, Sta. 53, 1901, no further data [
15–16 mm
long,
2–3 mm
wide]. One specimen (
MNHN
A372), Farasan Archipelago, Abulat Island (
19°58’ N
,
40°07’ E
), Sta. 5, NW off islet North, in
Porites
,
0–5 m
,
1951–1952
, Drach, Cherbonnier & Mercier, coll. [
12 mm
long,
1.8 mm
wide]. One specimen (
UF
3586), Farasan Islands, Zahrat Durakah (
16°50’09.24” N
,
42°18’22.68” E
),
2–6 m
, fringing reef, slope around sand,
11 Mar. 2013
, A. Anker, P. Norby & G. Paulay, coll. [
21 mm
long,
3 mm
wide]. One specimen (
UF
3499), Farasan Islands, Mahama Island, fringing slope (
16°29’21.12” N
,
41°56’39.48” E
),
4–17 m
, sand, reef rubble,
9 Mar. 2013
, A. Anker, P. Norby & G. Paulay, coll. [data used for variation].
Description
.
Syntypes
(
MNHN
289) distorted, partially dehydrated, most cirri missing, many chaetae broken (
Fig. 29
A–C). Body obconic, blunt anteriorly, tapered posteriorly, dorsum darker along anterior chaetigers (1–6/8), or dark throughout dorsal surface; some middle parapodia previously removed. Body
18–23 mm
long, 1.5–3.0 mm wide, 16 chaetigers.
Prostomium wider than long in smaller
syntypes
(
Fig. 29A
), as long as wide or slightly longer than wide in larger ones (
Fig. 29B, C
); slightly wider anteriorly (depending on pharynx eversion), lateral margins straight. Lateral antennae with ceratophores distinct, lateral antennae as long as prostomium (longer in smaller
syntypes
), as long as palps or slightly longer than them. Palpophores 2–3 times longer than palpostyles. Median antenna tapered, short, not reaching prostomial anterior margin, inserted between posterior eyes.
Eyes brownish, anterior ones slightly larger, about
1
/
10
as wide as prostomial width, missing in a smaller
syntype
, circular in another, emarginate in two specimens, and semilunar in two others, larger and more distant to each other than posterior round ones (semilunar in two
syntypes
).
Nuchal organs lobes horizontal C-shaped, visible dorsally in most
syntypes
; lateral ciliated bands dorsally visible in two
syntypes
. Tentacular cirri missing (reaching chaetiger
4 in
original description). Lateral cushions low, entire, longitudinal striae barely visible.
Pharynx fully exposed in one small
syntype
(
Fig. 29D
), partially exposed in another medium-sized one. Anterior margin with about 20 regular constrictions per side. Lateral vesicles not seen. Jaws single, yellowish, upper jaw twice larger than lower one, tapered, inserted slightly ahead of lower jaw.
FIGURE 29
.
Leocrates giardi
Gravier, 1900
, syntypes (MNHN 289). A. Smaller syntype, anterior region, dorsal view. B. Medium-sized syntype, anterior region, dorsal view. C. Larger syntype, anterior, region dorsal view. D. Smaller syntype, anterior region, ventral view. E. Chaetiger 7, left parapodium, anterior view (inset: notacicular lobe). F. Upper neurochaetal blade. G. Lower neurochaetal blades. Scale bars: A: 0.8 mm, B: 1.1 mm, C: 1.2 mm, D: 1 mm, E: 0.5 mm, F: 80 μm, G: 60 μm.
Dorsal cirri remaining in a few segments, without tips, shorter than body width. Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 20 per bundle, sometimes arranged in longitudinal fans, or as a bundle, subdistally denticulate, denticles fine. Notacicular lobes tapered; neuracicular lobes blunt, conical slightly longer than wide, sometimes as wide as long (
Fig. 29E
); ventral cirri surpassing neurochaetal lobe. Neurochaetae about 20 per bundle, blades bidentate, decreasing in size ventrally, 3–10 times longer than wide, guards approaching subdistal tooth (
Fig. 29F, G
).
Posterior region tapered. Preanal segment with dorsal cirri missing. Pygidium with anus terminal, anal cirri missing.
Oocytes about
100 µm
in diameter, visible in smaller and larger
syntypes
.
Variation
. One specimen (UF 3499) complete, straight. Body pale up to chaetiger 5, thereafter brownish;
16 mm
long,
2 mm
wide, 15 chaetigers (posterior end removed for molecular analysis; right parapodium of chaetiger 8 removed for parapodial features). Lateral antennae longer than prostomium, slightly longer than palps (
Fig. 30A
); palpophores twice longer than palpostyles; median antenna broken, inserted between posterior eyes. Eyes brownish, anterior ones twice larger than posterior ones. Longest tentacular cirri reaching chaetiger 7. Pharynx fully exposed (
Fig. 30
A–C), lateral vesicles tapered, upper and lower jaws exposed, hyaline, upper one twice larger than lower one. Notochaetae along chaetigers 5–15, many broken, denticulation fine; neurochaetae about 20 per bundle (
Fig. 30D
), blades 2–9 times longer than wide, guards approaching subdistal tooth (
Fig. 30D
, insets). Oocytes not seen, coelom full of damaged testis fragments and spermatids.Additional specimens
11–21 mm
long, collected in subtidal environments (
2–17 m
depth). Two specimens (UF 3499, 3586) smaller than
syntypes
(
16–21 mm
long) had pharynxes fully exposed, showing lateral vesicles, each with well-defined tips (tapered).
Remarks
.
Leocrates giardi
Gravier, 1900
resembles
L. claparedii
(
Costa
in
Claparède, 1868
) from the Mediterranean Sea by having prostomia wider anteriorly, notacicular lobes tapered, and middle chaetigers with about 20–30 neurochaetae. They differ, however, by the shape of notacicular and neuracicular lobes, and by the relative length of neurochaetal blades. In
L. giardi
notacicular lobes are tapered, neuracicular ones are as long as wide, and neurochaetal blades are 3–10 times longer than wide, whereas in
L. claparedii
notacicular lobes are blunt, neuracicular ones are wider than long, and blades are 2–8 times longer than wide.
The redefinition of
L. giardi
by
Pettibone (1970: 219–221
,
Figs 17–19
) must be discontinued because she did not study
type
material or topotype specimens, and the specimens she illustrated do not belong to
Leocrates
, as herein restricted, but to
Dalhousia
,
as redefined above.
Distribution
.
Red Sea
, subtidal mixed bottoms (
2–17 m
depth).