External ultrastructure of Manayunkia speciosa (Fabriciidae) from Uruguay River, Argentina

The external ultrastructure of Manayunkia speciosa Leidy, 1858 from specimens collected at the lower Uruguay River, South America is described using scanning-electron-microscopy. The branchial crown has a pair of semicircular lateral lobes, a pair of mediodorsal radioles and a pair of medioventral ones. Radiolar surfaces are ciliated. The faecal groove is observed on peristomium middorsally. The anterior margin of the anterior peristomial ring formed a rectangular lobe, with a ciliated band. Chaetal shape exemplifies the basic type of tapering cylinder. Two types of thoracic notochaetae: one wider distally, with a smooth handle, and covered on the surface by denticles, and other are significantly finer at the base and covered by thin structures with a free distal end. These structures were not previously recorded in Fabriciidae. Rows of 3 aligned uncini anteriorly projected are found in the thorax. Each uncinus presents a long manubrium which connects with the crest, extending to a main fang. The teeth of the crest are equal in size. The abdomen present 4 types of neurochaetae: one of small size than the other 3. In the abdomen 10-14 uncini form dense dorsal-transverse-lines. Each uncinus presents a short manubrium. The crest is covered with teeth of similar size.

[1]  L. Armendáriz,et al.  An introduced Polychaete in South America - Ecologic Affinities of Manayunkia speciosa (Polychaeta, Sabellidae) and the Oligochaetes of Uruguay River, Argentina , 2012 .

[2]  G. Rouse,et al.  Inference of phylogenetic relationships within Fabriciidae (Sabellida, Annelida) using molecular and morphological data , 2011, Cladistics : the international journal of the Willi Hennig Society.

[3]  L. Armendáriz,et al.  Manayunkia speciosa Leidy (Polychaeta: Sabellidae): introduction of this nonindigenous species in the Neotropical Region (Uruguay river, South America) , 2011, Biological Invasions.

[4]  M. A. Tovar-Hernández.  Phylogeny of Chone Krøyer, 1856 (Polychaeta: Sabellidae) and related genera , 2008 .

[5]  E. Kupriyanova,et al.  Yet another example of paraphyly in Annelida: molecular evidence that Sabellidae contains Serpulidae. , 2008, Molecular phylogenetics and evolution.

[6]  A. Bick.  Redescription of Pseudoaugeneriella nigra (Langerhans, 1880), new combination (Polychaeta, Sabellidae), with remarks on some characters of Fabriciinae , 2004 .

[7]  K. Fitzhugh.  New fan worm genera and species (Polychaeta, Sabellidae, Fabriciinae) from the western Pacific, and cladistic relationships among genera , 1998 .

[8]  G. Rouse.  New Fabriciola and Manayunkia species (Fabriciinae: Sabellidae: Polychaeta) from Papua New Guinea , 1996 .

[9]  E. Nishi.  A New Record of Fabricinuda bikinii (Hartman) (Polychaeta : Sabellidae : Fabriclinae) from Okinawa, Japan , 1996 .

[10]  A. Bick.  Reproduction and larval development ofManayunkia aestuarina (Bourne, 1883) (Polychaeta, Sabellidae) in a coastal region of the southern Baltic , 1996, Helgoländer Meeresuntersuchungen.

[11]  A. Giangrande,et al.  New species of Pseudofabriciola Fitzhugh, 1990 (Polychaeta: Sabellidae: Fabriciinae), from the Mediterranean Sea , 1994 .

[12]  G. Rouse.  New Fabriciola species (Polychaeta, Sabellidae, Fabriciinae) from the eastern Atlantic, with a description of sperm and spermathecal ultrastructure , 1993 .

[13]  K. Fitzhugh.  Further revisions of the Sabellidae subfamilies and cladistic relationships among the Fabriciinae (Annelida: Polychaeta) , 1991 .

[14]  A. Giangrande,et al.  Novafabricia bilobata sp. nov. (Polychaeta, Sabellidae, Fabriciinae) from the Mediterranean , 1991 .

[15]  P. Knight-Jones.  Behaviour, Setal Inversion and Phylogeny of Sabellida (Polychaeta) , 1981 .

[16]  Patrick Croskery.  The Freshwater co-occurrence of Eurytemora Affinis (Copepoda: Calanoida) and Manayunkia Speciosa (Annelida: Polychaeta): Possible relicts of a marine incursion , 1978, Hydrobiologia.

[17]  W. Brehm.  First Gulf of Mexico Coast Record of Manayunkia speciosa (Polychaete: Sabellidae) , 1978 .

[18]  G. Mackie,et al.  A polychaete, Manayunkia speciosa, from the Ottawa River, and its North American distribution , 1971 .

[19]  C. Holmquist.  Manayunkia speciosa Leidy — a fresh-water polychaete found in Northern Alaska , 1967, Hydrobiologia.

[20]  N. W. Britt.  A Brief Note on the Distribution of the Polychaete, Manayunkia Speciosa Leidy, in Western Lake Erie , 1965 .

[21]  J. K. Hiltunen.  Distribution and Abundance of the Polychaete, Manayunkia Speciosa Leidy, in Western Lake Erie , 1965 .

[22]  M. Pettibone.  FRESH-WATER POLYCHAETOUS ANNELID, MANAYUNKIA SPECIOSA LEIDY, FROM LAKE ERIE , 1953 .

[23]  O. Hartman.  Fabricinae (Feather-duster Polychaetous Annelids) in the Pacific , 1951 .

[24]  F. H. Krecker.  POLYCHAETE ANNELID WORMS IN THE GREAT LAKES. , 1939, Science.

[25]  O. L. Meehean.  MANAYUNKIA SPECIOSA (LEIDY) IN THE DULUTH HARBOR. , 1929, Science.

[26]  D. Kröhling,et al.  The parent material as the dominant factor in Holocene pedogenesis in the Uruguay River Basin , 2004 .

[27]  T. Bartolomaeus.  Structure and Formation of Thoracic and Abdominal Uncini in Fabricia stellaris (Müller, 1774) – Implication for the Evolution of Sabellida (Annelida) , 2002 .

[28]  G. Hartmann‐Schröder.  Annelida, Borstenwürmer, Polychaeta , 1996 .

[29]  K. Fitzhugh.  A systematic revision of the Sabellidae-Caobangiidae-Sabellongidae complex (Annelida, Polychaeta). Bulletin of the AMNH ; no. 192 , 1989 .

[30]  D. R. Spencer.  Occurrence of Manayunkia speciosa (Polychaeta: Sabellidae) in Cayuga Lake, New York, with Additional Notes on Its North American Distribution , 1976 .

[31]  C. Richard.  A Note on the Freshwater Polychaete, Manayunkia Speciosa Leidy, from California and Oregon , 1966 .

[32]  C. Börner.  Vorläufige Mittheilung über einige neue Aphorurinen und zur Systematik der Collembola , 1901 .