Exogone (Exogone) Mompasensis (Polychaeta : Syllidae : Exogoninae), A New Species From The Iberian Peninsula (Basque Country, Spain)

5 Pages·2002·1.8 MB·English

by  J Martinez

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
115(3):676-680. 2002.
Exogone (Exogone) mompasensis (Polychaeta: Syllidae: Exogoninae),
a new species from the Iberian Peninsula (Basque Country, Spain)
Julian Martinez, Idoia Adarraga, and Guillermo San Martin
(JM, lA) Sociedad Cultural INSUB. Museo Okendo, Apdo 3223. E-20080 San Sebastian, Spain,
e-mail: [email protected];
(GSM) Departamento de Biologia, Unidad de Zoologia, Facultad de Ciencias,
Universidad Autonoma de Madrid, Canto Blanco, E-28049 Madrid, Spain,
e-mail: [email protected]
—
Abstract. Exogone (Exogone) mompasensis, a new species of Exogoninae
(Syllidae, Polychaeta) from the intertidal substratum of Mompas, coastal area
located near San Sebastian (Iberian Peninsula), is described. The new species
is most notably characterized by the short antennae and shape ofstrongly mod-
ified compound spiniger-like chaetae. The new species is very similar to two
other species of the Southern Hemisphere.
Numerous specimens of an undescribed idue fixed with 10% formaldehyde in sea-
species of Exogone Orsted, 1845 were col- water. The specimens were removed and
lected during a study of the macrobenthic transferred to 70% ethanol. Observations
communities inhabiting the intertidal zone and measurements were made using a mi-
ofa polluted area in the San Sebastian coast croscope with interference contrast optics
(northeast of Iberian Peninsula). The new (Nomarsky). Drawings were made with a
species is similar to two species of the "camera lucida." Scanning electron micro-
Southern Hemisphere, Exogone (Exogone) scopical (SEM) micrographs were made af-
heterosetosa Mcintosh, 1885 and Exogone ter critical point drying and coating with
(Exogone) heterosetoides Hartmann- 300 A of gold at the SIDI (Servicio Inter-
Schroder, 1979; but differs, essentially, in departamental de Investigacion) of the
the size of the antennae and chaetal fea- Universidad Autonoma of Madrid. Types
tures. The new species is described, illus- are deposited in the collections of the Mu-
trated and discussed, and data on its ecol- seo Nacional de Ciencias Naturales of Ma-
ogy and biology are included. drid (MNCNM), Spain.
Materials and Methods Results and Discussion
Family Syllidae Grube, 1850
Specimens were obtained from samples
Subfamily Exogoninae Langerhans, 1879
collected monthly between May 1996 and
Genus Exogone Orsted, 1845
May 1997 at a station within the CoraIUna Exogone (Exogone) mompasensis,
elongata community, located on intertidal
new species
rocky substratum. This station is close to
the collector of the Mompas sewage net- Figs. 1, 2
—
work. An area of 400 cm- was chosen for Type locality. Mompas (San Sebastian,
each sample. All samples were collected by Spain, Iberian Peninsula) (43°20'10"N,
scraping the biota down to the rock surface. 01°57'40"W). —
MNCN
In the laboratory scrapings were washed Type material. Holotype:
mm MNCN
through a 0.5 mesh sieve and the res- 16.01/8710a. Paratypes: 16.01/
VOLUME 115. NUMBER 3 677
8710b, 11 specimens. All individuals from 16 \im long, distally minutely bidentate
Mompas (San Sebastian, Iberian Peninsula) (Figs. IF, G, 2C-E). Solitary dorsal simple
(43°20'10"N, 01°57'40"W)—, 8 Apr 1997. chaetae from anterior parapodia, unidentate
MNCN
Additional material. 16.01/ with some short subdistal spine on superior
8710c, 8 Apr 1997, one specimen with eggs face (Fig. IC), thickerposteriorly (Figs. IE,
MNCN
ventrally attached. 16.01/87lOd, 8 2G). Solitary ventral simple chaetae on pos-
Apr 1997, two females with juveniles at- terior parapodia, sigmoid, with long, robust
MNCN
tached. 16.01/87lOe, 8 Apr 1997, proximal tooth and short, small distal tooth
twojuvenile specimens. MNCN 16.01/8711, (Figs. II, 2H). Pharynx through 4-5 seg-
30 Jun 1996, one specimen with sexual ments; pharyngeal tooth on anterior rim
products. All individuals from Mompas (San (Fig. lA). Proventriculus through 3 seg-
Sebastian, Iberian Peninsula) (43°20'10"N, ments, with about 13-15 muscle cell rows.
01°57'40"W). Numerous specimens from Pygidium relatively large, semicircular,
around Australia of the species E. (E.) het- with 2 relatively short anal cirri, but longer
erosetosa and E. (E.) heterosetoides depos- than median—antenna (Fig. IB).
ited at the Austra—lian Museum (Sydney). Remarks. Exogone (Exogone) mompa-
Description. Body short, broad, 2.4 sensis, new species, is closely related to two
mm mm
long, 0.29 wide, 28 chaetigers, species ofthe Southern Hemisphere, E. (E.)
without color markings. Prostomium oval, heterosetosa Mcintosh, 1885 and E. (E.)
about 3 times wider than long; 4 eyes in heterosetoides Hartmann-Schroder, 1979.
open trapezoidal arrangement, apparently All three species are characterized by hav-
without eyespots. Median antenna longer ing compound spiniger-like chaetae strong-
than lateral antennae, cylindrical, distinctly ly modified, enlarged, distally expanded
shorter than prostomium and palps together, and spinose, with short, triangular blades.
originating between anterior eyes; lateral Exogone {E.) mompasensis differs from E.
antennae ovate, shorter than prostomium, (E.) heterosetosa in having shorter anten-
originating between median antenna and nae, both median and lateral antennae, in-
each anterior eye (Fig. lA). Palps broad, serted more anteriorly, longer palps and
relatively long, longer than prostomium, somewhat shorter proventriculus; also, the
fused all along their length, with a distal shafts of spiniger-like chaetae are thicker
distinct notch (Fig. lA). Peristomium sim- (see Mcintosh 1885, Haswell 1920). Exo-
ilar in length to following segments, cov- gone (E.) mompasensis differs from E. (E.)
ering posterior margin of prostomium; ten- heterosetoides in the shape of the median
tacular cirri ovoid, about 0.25 as long as antenna, bowl-shaped in E. (E.) heterose-
lateral antennae. Dorsal cirri similar to ten- toides, shape of dorsal and ventral simple
tacular cirri, somewhat longer, absent on chaetae, and in having bifid, smooth blades
chaetiger 2 (Fig. lA). First 3 parapodia on modified spiniger-like chatae instead un-
each with about 6 compound chaetae, all identate, with long spines on margin, as oc-
compound heterogomph falcigers, blades curs in E. (E.) heterosetoides (see Hart-
with proximal tooth long and small distal mann-Schroder 1979). One of the authors
tooth, short spines on margin (Figs. ID, (GSM) has studied numerous specimens of
2A), about 8-12 |xm long; parapodia from E. (E.) heterosetosa and E. (E.) heterose-
chaetiger 4 each with 4 similar compound toides from Australia, and is currently pre-
falcigers (Figs. IH, 2F), diminishing to 2 paring redescriptions of these Australian
on posterior parapodia, provided with nu- species; furthermore, E. (£".) heterosetoides
merous spines on shafts, and solitary is a long, slender species, with a filifrom
mm mm
strongly modified pseudospiniger (Fig. 2B), body (about 5 long, 0.2 wide, 56
distally expanded, spinose shaft, and blade chaetigers), and a small pharynx and pro-
triangular, large on bases, short, about 14— ventriculus in relation to its body length.
678 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
Fig. L Exogone (Exogone) mompasensis, new species. Holotype. A, anterior end. dorsal view. B. posterior
end, dorsal view. C, dorsal simple chaeta, anterior parapodium. D, compound falcigers, most anterior parapo-
dium. E, dorsal simple chaeta, posterior parapodium. F, modified spiniger-like chaeta, midbody. G, same, pos-
terior parapodium. H, compound falcigers, posterior parapodium. Scale bar: A, B = 114 |xm; C-I = 28 |jLm.
VOLUME 115, NUMBER 3 679
Fig. 2. Exogone (Exogone) mompasensis, new species. SEM. A, most anterior falcigers. B, fascicle of
chaetae, midbody. C-E, modified spiniger-like chaeta. F, falciger, midbody. G, dorsal simple chaeta, posterior
parapodium. H, ventral simple chaeta.
—
680 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
and E. (E.) heterosetosa and E. (E.) mom- laborated in the collection of the samples.
pasensis are species with proportionally The comments of two anonymous referees
mm
shorter and broader bodies (3—4 long, greatly improved the quality of the paper.
mm
0.23 wide, 30-40 chaetigers for E. (E.)
mm mm
heterosetosa, 2.4 long, 0.29 wide, Literature Cited
28 chaetigers for E. (E.) mompasensis) and
longer pharynx and proventriculus in rela- Audouin, J. V., & H. Milne-Edwards. 1833. Classifi-
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where the new species was collected is Nordwestkiiste Australiens (Zwischen Port
characterized by the abundance of the tan- Samson in Norden undPortHedlandinSiiden).
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taihde HbeixvaaplvleeosmpeercaiersobMuysttiala(sMtoeorrem,in18i9m4u)s, Haswellg,isWc.heAn.Mu19s2e0.umThuendExIongstointeuta.7—6:7J5ou-r2n1a8l.ofthe
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Acknowledgments schiede zwischen beiden Geschlechtern. Ar-
chiv fur Naturhgeschichte ll(l):20-23.
We wish to thank Jose Marfa Ruiz Pas- Poli, J. X. 1795. Testacea utriusque Siciliae eorumque
sicot, members of S. C. INSUB, who col- historic et anatomic. 2 Vol. Parma.