Diversidad de nematodos parásitos de peces en el Valle de Lerma, provincia de Salta (Argentina)

El objetivo de este trabajo de tesis fue ampliar y actualizar el conocimiento taxonómico y ecológico de los nematodos parásitos de peces en ambientes lóticos y lénticos pertenecientes a las Altas Cuencas de los ríos Bermejo y Juramento de la provincia de Salta.Asociación Parasitológica Argentin

Sprentascaris

Key to species of the subgenus <i>Sprentascaris</i> parasitic in Neotropical freshwater fishes <p>1 Males with caudal alae and six pairs of postanal papillae.......................................................2</p> <p>- Males without caudal alae and less than six pairs of postanal papillae.............................................3</p> <p> 2 Ventricular appendix/oesophageal length ratio in males and females is 1:0.16. Caudal alae well-developed. Vulva situated at 1.82–3.94 mm from anterior extremity, approximately at 1/3 of body length........................... <i>R.</i> (<i>S.</i>) <i>mahnerti</i></p> <p> - Ventricular appendix/oesophageal length ratio in males is 1:0.34 and in females 1:0.36. Caudal alae rudimentary. Vulva at short distance below oesophagus, at 0.40–1.06 mm from anterior extremity............................... <i>R.</i> (<i>S.</i>) <i>lanfrediae</i></p> <p>3 Lateral alae well developed (broad). In males, three pairs of postanal papillae......................................4</p> <p>- Lateral alae absent or rudimentary. In males, five pairs of postanal papillae........................................5</p> <p> 4 Symmetrical and equal lips. In males, 22 pairs of preanal papillae. In females, mature eggs embryonated, thin-shelled................................................................................................ <i>R.</i> (<i>S.</i>) <i>marano</i></p> <p> - Dorsal lips smaller than ventrolateral ones. In males, 16 pairs of preanal papillae. In females, mature eggs embryonated with rough shell and membranous striations................................................. <i>R.</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov.</b></p> <p> 5 Narrow oesophagus. Rounded tail in both sexes. Posterior end of males with ventral cuticular ornamentation. Length of spic- ules 0.14 mm. Parasites of Pimelodidae fishes................................................... <i>R.</i> (<i>S.</i>) <i>pimelodi</i></p> <p> - Oesophagus markedly broad. Pointed tail tip in both sexes. Males with smooth posterior ventral surface. Length of spicules between 0.15–0.25 mm.................................................................... <i>R.</i> (<i>S.</i>) <i>hypostomi</i></p>Published as part of <i>Ailán-Choke, Lorena Gisela, Ramallo, Geraldine & Davies, Dora, 2017, New species of Raphidascaris (Sprentascaris) (Nematoda: Anisakidae) in Rineloricaria steinbachi (Actinopterygii: Loricariidae) from Northwest Argentina, pp. 129-136 in Zootaxa 4231 (1)</i> on page 135, DOI: 10.11646/zootaxa.4231.1.10, <a href="http://zenodo.org/record/293599">http://zenodo.org/record/293599</a&gt

Raphidascaris (Sprentascaris) saltaensis Ailán-Choke, Ramallo & Davies, 2017, sp. nov.

<i>Raphidascaris</i> (<i>Sprentascaris</i>) <i>saltaensis</i> sp. nov. <p>(Figs 1–2)</p> <p> <b>Type material.</b> Holotype: female CH-FML # 07663; paratypes: eight males and five females, of which nine specimens were used for SEM, CH-FML # 0 7665.</p> <p> <b>Type host.</b> <i>Rineloricaria steinbachi</i> Regan, (Siluriformes: Loricariidae) (IBIGEO-I # 355–422).</p> <p> <b>Type locality.</b> La Caldera River (24°35´40.07”S; 65°22´11”W), La Caldera Department, province of Salta, Northwest Argentina.</p> <p> <b>Etymology.</b> The new species is named for its geographical location in the province of Salta.</p> <p> <b>Site of infection.</b> Intestine.</p> <p> <b>Infection parameters.</b> Prevalence: 11.94% (8/67); media intensity: 2.63 per fish.</p> <p> <b>Measurements.</b> Table 1.</p> <p> <b>General description.</b> Medium sized nematodes. Cuticle bearing transverse striations. Mouth aperture triangular, two ventrolateral lips and one dorsal lip. Lips well-developed and oval-shaped; dorsal lip slightly smaller than the two ventrolateral ones. Dorsal lip bearing two double papillae, ventrolateral lips with one double papilla, one single papilla and one amphid. Lips with lateral membranous margins forming finger-shaped protrusions at each side. Membranous extensions at base of lips. Interlabia absent (Figs. 1 A–C; 2A–C). Excretory pore slightly posterior to nerve ring level. Lateral alae present in both sexes, beginning in lateral region below lips and reaching almost to tail tip. Muscular oesophagus short with expanded posterior half. Caudal alae absent in both sexes. Ventriculus shorter than wide, ventricular appendix longer than wide. Both sexes with conical tail, its distal tip slender and sharply pointed.</p> <p>Adult males (eight specimens): Spicules equal, simple with pointed distal tips. Twenty pairs of caudal papillae. Preanal papillae: Sixteen subventral pairs; counting from cloaca opening, the first until the seventh pair are closer to each other than the remaining pairs. Adanal papillae: only one subventral pair. Postanal papillae: three small subventral pairs. Lateral alae present, without the partition in the caudal region. Caudal alae absent. Conical tail (Fig. 1 G).</p> <p>Adult female (six specimens): Vulva preequatorial, posterior to oesophagus end level (Fig. 1 E). Eggs ovalshaped, with thick and rough shell provided with membranous striations, mature eggs larvated (Figs. 1 D). Conical tail (Figs. 1 F; 2D).</p> <p> <b>Remarks.</b> <i>Raphidascaris</i> (<i>Sprentascaris</i>) <i>saltaensis</i> <b>sp. nov.</b> is distinguished from their congeners, by possessing 16 pairs of preanal papillae, membranous elevations below the lips, mature eggs with striated shell and the size of spicules (0.24 mm). For more detailed description of morphometric differences between the new species and other species of <i>Raphidascaris</i> (<i>Sprentascaris</i>) see Table 2.</p> <p> <i>Raphidascaris</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov</b>. differs from <i>R</i>. (<i>S</i>.) <i>mahnerti</i> and <i>R.</i> (<i>S.</i>) <i>lanfrediae</i> by the absence of caudal alae in the males; but shares this feature with <i>R.</i> (<i>S.</i>) <i>pimelodi</i>, <i>R.</i> (<i>S.</i>) <i>hypostomi</i> and <i>R.</i> (<i>S.</i>) <i>marano</i>. The new species presents lateral alae, which begins in the base of ventrolateral lips and extends almost to tail tip; no partition of this structure is observed, hence caudal alae are not present. <i>Raphidascaris</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov</b> differs from <i>R.</i> (<i>S.</i>) <i>pimelodi</i> and <i>R.</i> (S.) <i>hypostomi</i> by the presence of lateral alae, and by the number of postanal papillae pairs; <i>R.</i> (<i>S.</i>) <i>saltaensis</i> possess three pairs, while <i>R.</i> (<i>S.</i>) <i>pimelodi</i> and <i>R.</i> (<i>S.</i>) <i>hypostomi</i> present five pairs and lack lateral alae (Moravec 1998).</p> <p> <i>Raphidascaris</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov</b>. resembles <i>R.</i> (<i>S.</i>) <i>marano</i>, both species have lateral alae and three pairs of postanal papillae; but can readily be distinguished by the number of preanal papillae (16 vs. 22), the shape and size of lips (smaller and different lips with protrusions vs. longer, symmetrical, simple and equal lips), shape of eggs (rough-shelled vs. thin-shelled) and the spicule length (0.24 vs. 0.27) (Moravec 1998; Ramallo 2009).</p> <p> <b>Discussion.</b> Five genera of Anisakidae have been reported from the intestine of Neotropical freshwater fishes: <i>Goezia</i> (Zeder, 1800), <i>Hysterothylacium</i> (Ward and Magath, 1917), <i>Terranova</i> (Leiper and Atkinson, 1914), <i>Raphidascaroides</i> (Yamaguti, 1941) and <i>Raphidascaris</i> (Railliet and Henry, 1915). <i>Goezia</i>, <i>Hysterothylacium</i> and <i>Raphidascaris</i> show a broad geographical distribution including Mexico, Guyana, Venezuela, Brazil, Paraguay, Peru and Argentina; in contrast <i>Raphidascaroides</i> and <i>Terranova</i> were only recorded in Brazil and Venezuela (Moravec 1998). <i>Raphidascaris</i> has two subgenera: <i>Raphidascaris</i> (not in the Neotropical region), and <i>Sprentascaris</i> whose members are restricted to South America and were only reported in freshwater fishes (Ramallo 2009). Species of <i>Raphidascaris</i> (<i>Sprentascaris</i>) are characterized by possessing a cuticular ring without spines, the presence of small postlabial or interlabial cuticular elevations, absence of true interlabia; the excretory pore slightly posterior to nerve ring level, a muscular oesophagus with ventriculus and ventricular appendix; and no intestinal caecum (Moravec 1998).</p> <p> All species of <i>Raphidascaris</i> (<i>Sprentascaris</i>), except <i>R.</i> (<i>S.</i>) <i>lanfrediae</i>, have Siluriformes fishes as hosts. <i>Raphidascaris</i> (<i>S.</i>) <i>hypostomi</i> was isolated from specimens of the subfamilies: Hypostominae and Ancistrinae (all Loricariidae) (Moravec 1998). Eiras <i>et al.</i> (2010) found nematodes identified as <i>R.</i> (<i>S.</i>) <i>hypostomi</i> and <i>R.</i> (<i>S.</i>) <i>mahnerti</i> in <i>Metynnis lippincottianus</i> Cope (Characiformes, Serrasalmidae) from Brazil. <i>Raphidascaris</i> (<i>S.</i>) <i>mahnerti</i> was also reported in Loricariidae fishes; moreover Moravec <i>et al.</i> (1993) recorded the third larval stage of <i>Raphidascaris</i> (<i>Sprentascaris</i>) in the intestine of the cichlid <i>Geophagus brasiliensis</i> Quoy & Gaimard, (Perciformes, Cichlidae). The larva is probably conspecific with <i>R.</i> (<i>S.</i>) <i>mahnerti</i> and <i>G. brasiliensis</i> could be a paratenic host (Moravec 1998). This is not the only time <i>Raphidascaris</i> (<i>Sprentascaris</i>) was detected in cichlids; Melo <i>et al</i>. (2011) reported the adults of <i>R.</i> (<i>S.</i>) <i>lanfrediae</i> in <i>Satanoperca jurupari</i>. Possibly, this species share the host spectrum with <i>R.</i> (<i>S.</i>) <i>mahnerti</i>. Both species might be closely related but they can be differentiated by morphological features and their geographical distribution (Melo <i>et al</i>. 2011). <i>Raphidascaris</i> (<i>S.</i>) <i>pimelodi</i> is distinguished from other known species of the subgenus, because it was only detected in a pimelodid species.</p> <p> Although <i>R.</i> (<i>S.</i>) <i>marano</i> and <i>Raphidascaris</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov.</b> have both been recorded in Northwest of Argentina, they inhabit different fluvial systems; <i>R.</i> (<i>S.</i>) <i>marano</i> in Marapa River (basin of Sali River, provinces of Tucumán and Catamarca), and <i>R.</i> (<i>S</i>.) <i>saltaensis</i> <b>sp. nov</b>. in La Caldera River (basin of the Bermejo River, province of Salta). Ramallo (2009) proposed that <i>R.</i> (<i>S.</i>) <i>marano</i> would be an endemic species in Argentina, following the endemic character of its host, <i>H. cordovae</i> (Loricariidae). However, <i>H. cordovae</i> is synonymous of <i>H. paranensis</i>, thus the geographical distribution was extended to include Paraguay (Paraguay River basin, the main tributary of Paraná River) (Ferraris 2007). The new parasite species was found from <i>Rineloricaria steinbachi</i> (Loricariidae), whose geographical distribution is limited to southern Bolivia and northwestern Argentina, including the basins of the Bermejo (Rivers Bermejo, San Andrés, La Caldera, Mojotoro and Vaqueros and streams Gallinato and Pucheta), Juramento (Rivers Salado, Piedras, Arias Arenales, Rosario, Aguas Negras and Calchaquí), Pilcomayo River, and also the Dorado River basin (La Sala stream and Popayan River).</p> <p> In this paper, we propose the erection of the sixth species of <i>Raphidascaris</i> (<i>Sprentascaris</i>) from the Neotropical region and the second from Argentina. <i>Raphidascaris</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov</b>. differs from all congeners in the number of preanal papillae, the shape and size of lips, the egg’s shell and the spicules length. The new identification key presented in the article incorporates <i>R.</i> (<i>S.</i>) <i>lanfrediae</i> <i>,</i> <i>R.</i> (<i>S.</i>) <i>marano</i> <i>and</i> <i>R.</i> (<i>S.</i>) <i>saltaensis</i> <b>sp. nov.</b></p>Published as part of <i>Ailán-Choke, Lorena Gisela, Ramallo, Geraldine & Davies, Dora, 2017, New species of Raphidascaris (Sprentascaris) (Nematoda: Anisakidae) in Rineloricaria steinbachi (Actinopterygii: Loricariidae) from Northwest Argentina, pp. 129-136 in Zootaxa 4231 (1)</i> on pages 130-135, DOI: 10.11646/zootaxa.4231.1.10, <a href="http://zenodo.org/record/293599">http://zenodo.org/record/293599</a&gt

On the Evolutionary History of Philometridae (Nematoda: Dracunculoidea): Integrative Taxonomy Reveals Evidence of Character Diversification and Host–Parasite Cophylogenetic Patterns

(1) Background: Integrative taxonomy has been important in the comprehension of relationships among nematode parasites. Philometridae is a highly diverse family of these organisms, but poorly-known regarding genetic characterization and evolution. An integrative taxonomic analysis was performed to improve the knowledge of the evolutionary history of Philometridae. (2) Methods: Phylogenies were reconstructed based on genetic sequences alone and integrated with morphological/life history traits, which were phylogenetically mapped. The host–parasite cophylogeny was evaluated. (3) Results: Previously unpublished 28S rDNA sequences are given for some species. The phylogeny from this marker, although limited by data scarcity, showed similar patterns as that from 18S rDNA. Clades shared common features related to the structure of the esophagus and of the tail in males (especially the gubernaculum), site of infection, habitat, host taxa and geographic origin; most of these features were phylogenetically informative. The integrative phylogeny was better resolved. A cophylogenetic signal was present mainly in clades of freshwater species. (4) Conclusions: The speciation process in Philometridae is not unique or uniform; host capture, host–parasite co-evolution and allopatric (especially in freshwater) events may be occurring simultaneously in different lineages, places and times. Cases of plesiomorphy retention probably occur. Evolutionary convergence of poorly-informative characters is suggested, even though they are important for species diagnosis