Paula Marcotegui

Parasites and epibionts of grapsid crabs in Bahía Blanca estuary, Argentina

Epibionts and parasites were recovered from the grapsid crabs Cyrtograpsus angulatus and Neohelice granulata in the Bahia Blanca estuary, Argentina. Among epibionts, we identified a filamentous bacterium, the protozoan Epistylis sp., and the copepod Neocancrincola platensis on the gills; and the barnacles Balanus amphitrite and Balanus glandula as well as the bryozoan Conopeum reticulum on the caparace. Among endoparasites, we identified the acanthocephalan Profilicollis chasmagnathi in the hindgut, nematodes of the subfamily Acuariinae and Ascarophis sp. in the haemocoel, and an encysted cyclophyllidean cestode in the gut wall. Among microphallid digeneans, we found four metacercariae: Maritrema bonaerensis in the gills, muscle, haemocoel, and gonads, Maritrema orensensis in the gills, Levinseniella cruzi in the gonads, and Odhneria sp. in the muscle. Except for P. chasmagnathi, N. platensis , and M. bonaerensis , all other epibionts and digeneans represent new host records. This paper also presents novel information regarding the possible sites of infection for M. bonaerensis . Our results add relevant data about possible life cycles of helminths in the study area. Se recuperaron epibiontes y parasitos de los cangrejos grapsidos Cyrtograpsus angulatus y Neohelice granulata en el estuario de Bahia Blanca, Argentina. Entre los epibiontes, se identificaron una bacteria filamentosa, el protozoo Epistylis sp. y el copepodo Neocancrincola platensis en las branquias, y los cirripedios Balanus amphitrite y Balanus glandula y el briozoo Conopeum reticulum en el caparazon. Entre los endoparasitos, se identificaron el acantocefalo Profilicollis chasmagnathi en el intestino posterior, los nematodes Acuariinae y Ascarophis sp. en el hemocele y un cestode cyclophyllideo en la pared intestinal. Entre los digeneos microphallidos, se encontraron cuatro metacercarias: Maritrema bonaerensis en las branquias, el musculo, el hemocele y las gonadas, Maritrema orensensis en las branquias, Levinseniella cruzi en las gonadas y Odhneria sp. en el musculo. Excepto por P. chasmagnathi, N. platensis y M. bonaerensis , todos los otros epibiontes y digeneos representan nuevos registros para los hospedadores. Ademas, este trabajo presenta nuevos sitios de infeccion para M. bonaerensis y revela nuevos datos sobre los posibles ciclos de vida de los helmintos en el sitio de estudio.

Some Digeneans from Olrog's Gull Larus atlanticus Olrog, 1958 (Aves: Laridae) from the Bahía Blanca Estuary, Argentina

Abstract Five species of digeneans (4 Microphallidae, 1 Echinostomatidae) were recovered from a total of 85 Olrogs gulls, Larus atlanticus (dead chicks). Birds were collected from a breeding colony in the Bahía Blanca estuary, Argentina, during breeding seasons 2003 (n = 6), 2005 (n = 66), and 2006 (n = 13). Digeneans were identified as Maritrema bonaerensis, Maritrema orensensis, Odhneria odhneri, Levinseniella cruzi, and Himasthla escamosa. Except for M. bonaerensis, all other helminth species represent new host records, and all the digeneans reported constitute new locality records. Likely intermediate hosts for digeneans, such as Neohelice granulata (Crustacea: Decapoda), Cyrtograpsus angulatus (Crustacea: Decapoda), and Heleobia australis (Mollusca: Gastropoda), were also studied. The metacercariae of M. bonaerensis were found in the crabs N. granulata and C. angulatus, and cercariae closely resembling those of M. bonaerensis, L. cruzi and H. escamosa were found in the mollusc H. australis.

Morphological and molecular identification of the fish-borne metacercaria of Ascocotyle (Phagicola) longa Ransom, 1920 in Mugil liza from Argentina

This is the first report of Ascocotyle (Phagicola) longa Ransom, 1920 (Digenea: Heterophyidae) in Argentina confirmed by morphological and molecular studies. The metacercaria was found encysted in myotomal musculature, heart and mesentery of the mullet Mugil liza (Pisces: Mugilidae) from Samborombon bay. We provide a morphological description of the metacercaria which we identified using species-specific primers for A. (Phagicola) longa and nucleotid sequence. This worldwide parasite has been reported as one of the causative agents of heterophyiosis, an emerging fish-borne disease of humans, contracted by the consumption of raw mullet. The discovery of A. (Phagicola) longa in Argentina represents a warning of the potentially great impact of this parasite on public health.

Two new species of Syndesmis (Platyhelminthes, Rhabdocoela, Umagillidae) from the sea urchin Pseudechinus magellanicus (Echinodermata, Echinoidea) in the Southwestern Atlantic Ocean

In this paper, we describe two new species of Syndesmis living in Pseudechinus magellanicus in the Southwest Atlantic Ocean. The new species have a long stylet in the male reproductive system, which is different from that of the known species of the genus. Specimens of Syndesmis selknami n. sp. have a ∼220-μm-long stylet (∼1/3 of the body length, 0.69 mm). This ratio is unique because only four species (Syndesmis echinorum, Syndesmis rubida, Syndesmis inconspicua and Syndesmis echiniacuti) have similar stylet lengths but are larger in body sizes (3–5 mm). Specimens of Syndesmis aonikenki n. sp. have a ∼148-μm-long stylet (∼1/10 of the body length, 1.11 mm). Syndesmis pallida has a similar ratio but the uterus is located posteriorly, and the filament glands are very small and located in the posterior region of the body. These are the first flatworms reported parasitizing Pseudechinus magellanicus.

Trichodinids (Ciliophora) of Corydoras paleatus (Siluriformes) and Jenynsia multidentata (Cyprinodontiformes) from Argentina, with Description of Trichodina corydori n. sp. and Trichodina jenynsii n. sp.

During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombon River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370–380°. Trichodina jenynsii is characterized by curved blades and prominently-shaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.

Screening for WSSV in crustacean from marine areas of Buenos Aires, Argentina

In total 374 specimens corresponding to four species of shrimp: Artemesia longinaris, Pleoticus muelleri, Peisos petrunkevitchii, Palaemon macrodactylus, and two species of crabs: Neohelice granulata and Cyrtograpsus angulatus were studied in the search of white spot syndrome virus (WSSV). The crustaceans were collected in the estuary of Bahia Blanca, the port of Mar del Plata and the Samborombon Bay, Argentina, between 2010 and 2014. A polymerase chain reaction (PCR) analysis in all of them has not detected any virus presence. These new results suggest that the discovery of infected shrimp in 2008-09 in the Bahia Blanca estuary may have been a one-time local event, promoted by special conditions of seawater temperature inside the estuary, coincident with the presence of a virus carrier or transporter. To determine if the virus was finally installed in the estuary of Bahia Blanca more screening are needed coming from a larger number of shrimp samples. These studies will be necessary mainly in A. longinaris (Penaeidae) since this family of shrimps is most susceptible to be affected by WSSV.

Riggia puyensis n. sp. (Isopoda: Cymothoidae) parasitizing Chaetostoma breve and Chaetostoma microps (Siluriformes: Loricariidae) from Ecuador

A new isopod was found parasitizing Chaetostoma breve and Chaetostoma microps from the Puyo and Bobonaza rivers. The parasite found belongs to the Cymothoidae family and could be located within the genus Riggia instead of Artystone by the presence of abdominal plates fused with the telson. The specimens found represent a new species, Riggia puyensis n. sp., and could be distinguished from Riggia cryptocularis by the presence of developed eyes. The main difference of the new specie from Riggia nana and Riggia brasiliensis is the size, bigger compared with the first and smaller compared with the last species. Riggia acuticaudata have the maxilliped with simple setae, the palp without spination, and maxillule with five spines (two terminal and three subterminal) instead in R. puyensis n. sp. the maxilliped have plumose setae, the palp have spination (with one apical spine, two setae on middle article and one in the basal article) and the maxillule have five spines: two terminal, two subterminal and other spine lower to the others. Riggia paranaensis have similar size, same number of segments in the antena, and similar maxilla to R. puyensis n. sp., but the antennule in the new specie have seven segments instead 6 in R. paranaensis, the antennule and antenna present spines not mentioned in R. paranaensis. Besides, the relative position of the mandible in R. puyensis n. sp. is different compared with R. paranaensis, the maxillule have the same number of spines but with different disposition, and the maxilliped have simple setae in R. paranaensis but those are plumose in the new specie.