A new cryptic species of Aponurus Looss, 1907 (Digenea: Lecithasteridae) from Mediterranean goatfish (Teleostei: Mullidae)

Abstract

The status of the trematode Aponurus laguncula Looss, 1907 in the western Mediterranean is re-assessed by means of a comparative morphological study and rDNA sequences based on newly collected material. A. laguncula (sensu stricto) is redescribed from Trachinus draco L. and a new cryptic species of the 'A. laguncula complex', Aponurus mulli n. sp., is described on the basis of abundant material from Mullus barbatus L. (type-host) and M. surmuletus L. off the Spanish Mediterranean coasts. The new species is differentiated from A. laguncula (sensu stricto) by its: significantly larger, elongate body, with maximum width at the level of the ventral sucker; shorter forebody; distinctly larger sinus-sac, seminal receptacle and seminal vesicle, with the latter also being more elongate; vesicular pars prostatica; more anteriorly located vitellarium, which consists of eight globular follicles; and distinctly smaller eggs, which are also smaller in relation to body size and have both their opercular and anopercular poles rounded. The variability and the allometric growth of the morphological characters in the new species were studied in detail, resulting in additional distinguishing features. Sequences of the large subunit rRNA (28S) gene (domains D1-D3) and ITS2 rRNA gene region for the new species have been submitted to GenBank in order to enhance future studies on species differentiation within the 'A. laguncula complex'.

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“…So far, members of the genera Aponurus, Holorchis, Derogenes, Lecithaster, Lasiotocus, Proctotrema and Anisocladium have been reported in Mullus barbatus in the Mediterranean Sea (Bray, 1985;Bartoli & Bray, 1996;Bartoli, Gibson & Bray, 2005;Carreras-Aubets et al, 2011;Carreras-Aubets et al, 2012;Debenedetti et al, 2013;Radujkovic & Sundic, 2014). Expect Proctotrema, the absence of these digenean parasites in this study could be resulted from the lack of the final and intermediate hosts in our sampling area.…”

“…In spite of their ecological and economical importance in the region, the research on the parasitic fauna and parasite ecology of the fish are still not enough. There are many parasitological studies on Mullus barbatus from the Mediterranean and Atlantic Seas (Essafi, Raibaut & Boudaoud-Krissat, 1983;Abo-Esa, 2007, Paradiznik & Radujkovic, 2007Ramdane & Trilles, 2010; Carreras-Aubets, Repulles-Albelda, Kostadinova & Carrassón, 2011;Carreras-Aubets, Montero, Kostadinova & Carrassón, 2012;Debenedetti, Madrid & Fuentes, 2013;Radujkovic & Sundic, 2014). On the other hand, studies on the parasite fauna of Mullus barbatus or M. barbatus ponticus in Black Sea are limited (Ovcharenko & Yurahno, 2006;Gaevskaya, 2012).…”

Taxonomy, systematics and phylogenetic status of Faustulidae from corallivorous fishes in the Tropical Indo-west Pacific

“…In terms of lines per taxon, the Northern European Seas Province (2) is the most studied region, but the Arctic (1), Mediterranean Sea (4) and possibly the Cold Temperate Northwest Atlantic (5) and the Tropical Northwest Atlantic (12), have very similar levels of effort. The effort in the southwestern Atlantic (13,14,47,48) is considerably less and no records were recovered from the North Brazilian Shelf Province (13). The best known fauna from this region is Warm Temperate Southwestern Atlantic (47).…”

“…Cycle sequencing of purified DNA was carried out using ABI Big Dye™ v.3.1 chemistry following the manufacturer's recommendations, using the same primers used for PCR amplification as well as the additional 28S primers 300F (5′-CAA GTA CCG Sequencher™ version 4.5 (GeneCodes Corp.) was used to assemble and edit contiguous sequences and the start and the end of the ITS2 region were determined by annotation through the ITS2 Database (Keller et al 2009;Ankenbrand et al 2015). 14 The partial ITS2 and 28S rDNA sequences generated were aligned using MUSCLE version 3.7 on MEGA 7 (Edgar 2004) with ClustalW sequence weighting and UPGMA clustering for iterations 1 and 2. The resultant alignments were refined by eye using MESQUITE (Maddison & Maddison, 2015) and the ends of each fragment were trimmed to match the shortest sequence.…”

“…Recent molecular studies of trematodes of fishes have shown that cryptic species occur commonly in this class of parasites and there are now reports of what have been interpreted as cryptic species for multiple trematode families (e.g. [7][8][9][10][11][12][13][14]). Cryptic species are frequently associated with closely related hosts, but may also be found in allopatry, and, occasionally, sympatrically in individual host species [15,16].…”