Kotorella pronosoma (Stossich, 1901) Euzet and Radujkovic, 1989

Marmolejo-Guzman, Linda Yacsiri G., Iv, David, Hern, an G., andez-Mena, Castellanos-Martínez, Sheila & Aguirre-Macedo, M. Leopoldina, 2022, Linking phenotypic to genotypic metacestodes from Octopus maya of the Yucatan Peninsula, International Journal for Parasitology: Parasites and Wildlife 19, pp. 44-55 : 52

4.2. Kotorella pronosoma

The genus Kotorella ( Euzet and Radujkovic, 1989) was previously assigned to the genus Otobothrium or Nybelinia in the Tentaculariidae family. However, at present, it is considered a monotypic genus with a single recognized species Kotorella pronosoma ( Stossich, 1901) ( Euzet and Radujkovic, 1989) . Beveridge et al. (2017) stated that this species is distributed around the world. The adult stages are found in the stomach and spiral valve, while larval stages infect the stomach and mesentery of teleost fish ( Palm and Overstreet, 2000). The specimens recorded in O. maya belong to the genus Kotorella because they exhibited typical morphological characteristics of the genus, such as scolex elongated, craspedote, and velum, four elongated bothria, pars post bulbosa absent, bulbs oval, and short tentacles ( Fig. 2D and E ; Fig. 3B). In this study, three sequences (995, 1444, and 1445 bp) were obtained from the 18S rDNA and two more (545 and 553 bp) from 28S rDNA, respectively. After comparing all the sequences of K. pronosoma infecting O. maya with those available in the public database, 100% of the similarity was obtained with larvae and adults of K. pronosoma from the Gulf of Mexico infecting Syacium papillosum and Hypanus say ( Olson et al., 2010) . Both fishes act as intermediate and definitive hosts, respectively, for K. pronosoma ( Palm and Overstreet, 2000; Olson et al., 2010; Vidal-- Martínez et al., 2019). An unexpected result showed that our sequence had a similarity percentage of 94.67–95.05% in 28S and 97.25% in 18S rDNA with Kotorella specimens found in the Indian Ocean. The phylogenetic analyses showed that the K. pronosoma from O. maya grouped without genetic differences with the K. pronosoma from the Gulf of Mexico. In contrast, they do not have a close phylogenetic relationship with Kotorella from the Indian Ocean. This phylogenetic result has two implications: 1) as the representatives of the genus were not grouped in a single clade, then Kotorella could be a non-monophyletic genus, result that had also been reported in the phylogeny of Olson et al. (2010); 2) the genetic and phylogenetic differences suggest that Kotorella is not a cosmopolitan genus and species. Therefore, a detailed review of the diagnostic characteristics of the genus is encouraged to avoid ambiguities in its identification.

Figures

Fig. 2. Schematic drawings and photographs of the stained specimens of cestode parasitizing Octopus maya. Trypanorhyncha (A–D): A- Eutetrarhynchus sp.; B. Kotorella pronosoma; C- Nybelinia sp.; D- Prochristianella sp. Onchoproteocephalidea (E–G): E- Acanthobothrium sp.; F- Phoreiobothrium sp.; G- Prosobothrium sp.- Abbreviations: as = apical sucker; bot = bothridia cc = calcareous corpuscles; lo = loculi; pb = pars bulbosa; pbo = pars bothrialis; ppb = pars postbulbosa; ps = pedunculus scolecis; pv = pars vaginalis; sc = scolex; sp = septa; st = strobilo; vel = velum.