Check list of gnathostomulids from the Canary Archipelago (NE Atlantic Ocean)

              Rev. Acad. Canar. Cienc, Vol. XXIV. 51-54 (diciembre de 2012)
CHECK-LIST OF GNATHOSTOMLLIDS
FROM THE CANARY ARCHIPELAGO (NE ATLANTIC OCEAN)
Rodrigo Riera*
Centro de In\ estigaciones Medioambientales del Atlantico
Arzobispo Elias Yanes 44, 38206 La Laguna, Tenerife. Canary Islands. Spain
*email: rodrigoCfl cimacanarias.com
RESLMEN
Un total de cinco especies de gnatostomulidos han sido citadas para el archipielago ca-nario.
Las especies son: Haploguathia rosea (Sterrer. 1969). H. nibenima (Sterrer. 1966).
Paragnathiella thfoliceps Sterrer, 1997, Lahidognathia longicollis Riedl. 1970 y Austrogna-thia
clavigera Sterrer, 1997. Dos especies son endemicas {Paragnathiella trifoliceps y Aus-trognathia
clavigera) y unicamente han sido recolectadas en su localidad tipo. El resto de
especies se caracterizaron por presentar una distribucion anfiatlantica (Z.. longicollis) y cos-mopolita
(//. rosea y H. ruberrima).
Palabras clave: Gnathostomulida. intersticial, sedimento. submareal, islas Canarias,
Oceano Atlantico
ABSTR.\CT
Five species of gnathostomulids ha\ e been recorded from the Canary archipelago.
These species are Haplognathia rosea (Sterrer, 1969), H. ruberrima (Sterrer, 1966). Parag-nathiella
trifoliceps Sterrer, 1997. Labidognathia longicollis Riedl, 1970 and Austrognathia
clavigera Sterrer, 1997. Two species are endemisms. only recorded in type localit\- {P. trifo-liceps
and A. clavigera). The remaining taxa are amphiatlantic (I. longicollis) and cosmo-politan
(//. rosea and H. ruberrima).
Key words: Gnathostomulida. interstitial, sediment, subtidal. Canary Islands,
Atlantic Ocean.
INTRODUCTION
Gnathostomulids are interstitial organisms, with an average length of 1.5 mm and
a diameter ranging from 0.045 to 0.065 mm. Most of gnathostomulids live in marine
anoxic sandy sediments, being common inhabitants of the RPD layer (REISE [4]). Up
to now. almost 100 species of this taxonomic group has been described worldwide
(STERRER [12]).
51
In Canary Islands, STERRER [11] found several gnathostomulid species in Las Can-teras
beach (Gran Canada) in February 1996, even he discovered two new species (Parag-nathiella
trifoliceps and Austrognathia clavigera), one of them belonging to a new genus
{Paragnathiella). Posteriorly, during a pilot study prior of one-year study basis conducted in
Los Cristianos beach, several specimens belonging to two gnathostomulid species were
recorded. A taxonomic detailed study revealed that they correspond to previously collected
species by STERRER [11] in Gran Canaria: Haplognathia rosea and H. ruberrima.
MATERIAL AND METHODS
Sediment samples were collected by hand and snorkelling, and extracted following
methodology explained in STERRER [9, 10]. Samples from shallow subtidal seabeds of Los
Cristianos beach were taken following methods described in detail by RIERA [6].
SYSTEMATICS
PHYLUM GNATHOSTOMULIDA Ax, 1956
Order FILOSPERMOIDEA Sterrer, 1972
Family Haplognathiidae Sterrer, 1972
Genus Haplognathia Sterrer, 1970
Haplognathia rosea (Sterrer, 1969)
Pterognathia rosea STERRER [8]
Haplognathia rosea STERRER [1 1]: 186, Figs 1 A, 2A.
Studied material.- Los Cristianos bay (Tenerife), coordinates (28°02'67"N, 16''42'64"W), 4 m depth,
fine sands with very sparse Cymodocea nodosa patches, April 2000, 2 ind.
Distribution.- Cosmopolitan, collected in North Sea (STERRER [8]), Atlantic Ocean (STER-RER
[11]) and Pacific Ocean (STERRER [10]). This species was recorded in two sites in Las
Canteras beach in shallow seabeds (2-3 m depth) with sparse C. nodosa patches and. rhy-zomes
(STERRER [11]).
Haplognathia ruberrima (Sterrer, 1966)
Pterognathia ruberrima STERRER [7]
Pterognathia grandis KIRSTEUER [3]
Haplognathia ruberrima STERRER [11]: 186, Figs: IB-G, 2B-C; Table 2.
Studied material.- Los Cristianos bay (Tenerife), coordinates (28°02'67"N, 16°42'64"W), 4 m depth,
fine sands with very sparse Cymodocea nodosa patches, April 2000, 2 ind.
Distribution.- Cosmopolitan. North Sea (STERRER [8]), Atlantic Ocean (STERRER [11])
and Pacific Ocean (STERRER [10]). This species was recorded in Las Canteras beach, at
shallow seabed (2-3 m depth) fine sands with sparse C. nodosa (STERRER [11]).
52
Order BURSOVAGINOIDEA Sterrer. 1972
Suborder Scleroperalia Sterrer. 1972
Family Agnathieliidae Sterrer, 1972
Genus Para^^nathiella Sterrer. 1997
Paragnathiella trifoliceps Sterrer, 1997
Paragmithiella trifoliceps STERRER [1 1]: 189. Figs. 3A-L, 4A-E; Table 3.
Distribution.- Canarv Islands. The type locality is Las Canteras beach, in fine sands with
sparse Cymodoccci nodosa at 2-3 m depth (STERRER [11]).
Family Mesognathariidae Sterrer. 1972
Genus Labidognathia Riedl. 1970
Labidognathia longicolUs Riedl. 1970
Labidognathia longicolUs RIEDL [5]: 229. fig. 1; STERRER [11]: 193, Figs. 5A-E. 6A-B;
Table 4.
Distribution.- Amphiadantic (RIEDL [5], STERRER [11]). This species has been recorded at Las
Canteras beach, in fine sands with sparse Cymodocea nodosa at 2-3 m depth (STERRER [11]).
Suborder CONOPHOR.\LL\ Sterrer, 1972
Family Austrognathiidae Sterrer, 1971
Genus Austrognathia Sterrer. 1965
Aiistrognathia clavigera Sterrer. 1997
Austrognathia clavigera STERRER [11]: 194. Figs. 7A-0. 8A-C. Table 5.
Distribution.- Canary Islands. The type locality is Las Canteras beach, in fine sands with
sparse Cymodocea nodosa at 2-3 m depth (STERRER [11]).
DISCUSSION
Most of taxonomic groups from interstitial fauna, commonly known as meiofauna. re-mains
scarcely known in the Canar\' archipelago and ha\ e not been extensi\ ely studied, such
as, gastrotrichs. turbellarians. harpacticoid copepods, acari. oligochaetes. priapulids. kinor-rhynchs.
among others. Though se\ eral taxonomic works on free-li\ ing marine nematodes
and polychaetes has been published from two sampling locations on the south coast of Tener-ife
(Los Abrigos del Poris and Los Cristianos) in the last decade (RIER.A [6]) and several sea-grass
meadows throughout the Canary archipelago (BRITO-CASTRO [2]). as well as.
taxonomic studies carried out in the benthos laboratorv* of the University of La Laguna (De-partment
ofAnimal Biology) coordinated by Dr. Jorge Niifiez. most of the meiofaunal groups
have only recorded in a limited number of sampling stations conducted by taxonomists dur-ing
non-intensive field sur\ eys. Hence, taxonomic extensive studies are necessar>' to carr>
out in order to increase the knowledge of canarian marine biodiversity.
Gnathostomulids are one of the interstitial taxonomic groups that still remain oxer-looked
in the Canar\' archipelago. An increase number of gnathostomulids records is expected
53
in the next years, though specific sampHng campaigns are necessary to be conducted because
of ecologic requirements of this group (e.g. hypoxic or anoxic sandy sediments) (REISE [4]).
Current assemblages of gnathostomulid endemisms {Paragnathiella trifoliceps and
Austrognathia clavigera) could be considered endangered, since they were recorded solely in
the sparse Cymodocea nodosa seagrass meadow at Las Canteras beach (Gran Canaria). In the
last years, a dramatic reduction of C. nodosa meadow has been observed; even demonstrated
by genetic analyses that confirmed higher fragmentation and smaller meadow size in this lo-cation
(ALBERTO et al [1]).
ACKNOWLEDGEMENTS
To Viceconsejeria de Medio Ambiente del Gobierno de Canarias for coordinating
BIOTA MARINO programme. To Leopoldo Moro and Rogelio Herrera (Canarian Govern-ment)
for their continuous encouragement in the study of canarian marine biodiversity.
REFERENCES
[I] ALBERTO, P., S. ARNAUD-HAOND, CM. DUARTE & E.A. SERRAO. 2006. Ge-netic
diversity of a clonal angiosperm near its range limit: the case oi Cymodocea nodosa
at the Canary Islands. Marine Ecology Progress Series, 309: 1 17-129.
[2] BRITO-CASTRO, M.C. 2002. Estudio de las comunidades intersticiales del sebadal
(^Cymodocea nodosa^ en Canarias, con especial referenda a anelidos poliquetos. Tesis
Doctoral, curso 1998-1999. Servicio de Publicaciones de la Universidad de La Laguna.
[3] KIRSTEUER, E. 1969. On some species of Gnathostomulida from Bimini, Bahamas.
Amer Mus. Novitates, 2356: 1-21.
[4] REISE, K. 1981. Gnathostomulida abundant alongside polychaete burrows. Marine Ecol-ogy
Progress Series 6: 329-333.
[5] RIELD, R. 1970. On Labidognathia longicollis nov. gen. spec, from the West Atlantic
Coast (Gnathostomulida). Int. Revue ges. Hydrobiol. 55: 359-376.
[6] RIERA, R. 2004. Biodiversidad meiofaunal de las playas de Los Abrigos del Ports y de
Los Cristianos en la isla de Tenerife. Estructura y dindmica de sus comunidades. Uni-versity
of La Laguna, Ph-D Thesis, 486 pp.
[7] STERRER, W. 1 966. Gnathostoula paradoxa und vertreter von Pterognathia (ein neues
Gnathostomuliden-Genus) von der schwedischen Westkiiste. Arkivfor Zoologi, Serie 2,
18(16): 405-413.
[8] STERRER, W. 1969. Beitrage zur Kenntnis der Gnathostomulida I. Anatomic und Mor-phologic
des Genus Pterognathia Sterrer. Arkivfor Zoologi, Serie 2, 22(1): 1-125.
[9] STERRER, W. 1971. On the biology of Gnathostomulida. Vie et Milieu, suppl 22: 493-508.
[10] STERRER, W. 1991. Gnathostomulida from Fiji, Tonga and New Zealand. Zoologica
Scripta,20: 107-128.
[II] STERRER, W. 1997. Gnathostomulida from the Canary Islands. Proceedings ofthe Bi-ological
Society of Washington, 1 1 0(2): 1 86- 1 97.
[12] STERRER, W. 2006. Gnathostomulida (unsegmented marine worms). In cLS. John
Wiley & Sons Ltd, Chichester.
54