Revision of Autolytinae (Syllidae: Polychaeta).
Author
Nygren, Arne
text
Zootaxa
2004
680
1
314
journal article
42299
10.5281/zenodo.157809
43595c87-02cf-47ba-ba28-0cb07de78adc
1-877354-52-X
157809
471A4E52-4C92-44F8-AB38-CD03071C0067
Paraprocerastea
San Martín & Alós, 1989
Paraprocerastea
San Martín & Alós, 1989
: 872
–877, fig. 1A–L.
Linnean name definition
.
Type
species
Paraprocerastea crocantinae
San Martín & Alós, 1989
by original designation.
PhyloCode definition
. No name definition provided.
Apomorphies
. Clade supported by four morphological apomorphies (
Fig. 4
): 1)
cirrostyles egg shaped
(character 15), other most parsimonious reconstructions (MPRs) possible, character state change is a parallelism; 2)
simple dorsal chaetae of medium thickness
(character 36); 3)
simple dorsal chaetae even
(character 37), character state change is a reversal; 4)
pharynx sinuation minute
(character 39), character state change is a parallelism.
Paraprocerastea crocantinae
San Martín & Alós, 1989
(Fig. 44A–D)
Paraprocerastea crocantinae
San Martín & Alós, 1989
: 872
–877, fig. 1A–L.
San Martín 2003
: 458
–460, fig. 250A–L.
Material examined
.
Spain
:
holotype
MNCN
16.01/620, Cabo de Creus, cala Taballera, Gerona, calcareous concretions of
Mesophyllym lichenoides
and
Lithophyllum expansum
,
12 m
; 1
paratype
on slide
MNCN
16.01/622, off Los Genoveses inlet, Alméria, rhizomes of
Posidonia oceanica
,
3 m
,
June 1986
.
Diagnosis
.
Procerini
with only simple chaetae, and with dorsal cirri on all segments.
Description
.
Holotype
complete, length
2.5 mm
for 18 chaetigers (Fig. 44A) (length in
paratype
3.4 mm
for 33 chaetigers), width excluding parapodial lobes
0.3 mm
at level of proventricle. Preserved material brownish, no colour markings. Ciliation not assessed. Body shape, excluding parapodial lobes, cylindrical in transection, venter flattened. Body width fairly constant with tapering end (Fig. 44A).
Prostomium rounded rectangular, wider than long. Four eyes, with lenses, in trapezoid arrangement. Eyes separated; eye spots present. Palps do not project in front of prostomium. Palps fused. Nuchal epaulettes not possible to assess, occipital flap not observed.
Median antenna reaching chaetiger 3–4. Lateral antennae 2/
3 in
length of median antenna. Dorsal tentacular cirri and first dorsal cirri, length 1/2 of lateral antennae. Ventral tentacular cirri 1/2 as long as dorsal pair. Alternation in direction of cirri not assessed. Cirri from chaetiger 2, of equal length, c. 1/8 of body width excluding parapodial lobes. Small cirrophores present on tentacular cirri, and first dorsal cirri; cirrophores otherwise absent. Lateral antennae, tentacular cirri and first dorsal cirri club shaped, median antenna cylindrical, dorsal cirri from chaetiger 2, ovoid to egg shaped.
Parapodial lobes rounded, small. All chaetigers with 1–2 aciculae. Chaetigers 1–4 with 4 simple chaetae, following chaetigers with 3 simple chaetae (Fig. 44B). Denticulation present along "fusion line" (Fig. 44B). Simple chaetae with small distal tooth; serration absent. Single mediumthick bayonet chaetae (Fig. 44B), distally denticulated, beginning at chaetiger 1.
Pharynx with minute sinuation anterior to proventricle. Trepan in tentacular segment, with 19–20 equal teeth (
23 in
paratype
) (Fig. 44C, D). Basal ring absent; infradental spines absent. Proventricle equal in length to 1.5 segments in chaetiger 3–4 (
4–5 in
paratype
) with 19–22 rows of square shaped muscle cells. Two anal cirri (Fig. 44A), as long as 1/3 of body width at level of proventricle.
Reproduction
. Unknown.
Habitat
. Calcareous concretions of
Mesophyllym lichenoides
and
Lithophyllum expansum
,
12 m
.
Distribution
. Mediterranean coast of
Spain
.
Remarks
.
Paraprocerastea crocantinae
is most similar to taxa in
Procerastea
, in both general body outline and in the shape of the simple chaetae. Dorsal cirri is, however, absent in atokes of
Procerastea
from chaetiger 2, while present on all chaetigers in
P. c ro cantinae
. The bayonet chaetae in
Procerastea
is of the thick, distally dilated,
type
, while a thinner, and even bayonet chaetae is present in
P. crocantinae
. The bayonet chaetae is, however, not as thin as in e.g.
Autolytus
, and is therefore called mediumthick.
Paraprocerastea crocantinae
was described as having an occipital flap covering most of prostomium; this could not be confirmed.