Acanthobothrium sp.

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 : 53

4.5. Acanthobothrium sp.

Specimens of Acanthobothrium sp. infecting O. maya from the Yucat´an Peninsula were originally misidentified as Phyllobothrium sp. in prospecting studies (Aguirre-Macedo, com. pers.). The collection of fresh material in this study allowed a better observation of the characteristics of the parasites. The new material matched those previous records and none of them showed folds, curvatures, and ripples in the bothridal part as in Phyllobothrium ( Khalil et al., 1994) . Therefore, it is dismissed that the parasites found in O. maya ( Fig. 2L–O ; Fig. 3E) belong to the genus Phyllobothrium yet were recorded in Octopus vulgaris ( Gestal et al., 1998) . In contrast, the parasites infecting O. maya showed a scolex with an apical sucker, four bothria, each one divided into three loculi with two transverse septa, large strobila with calcareous corpuscles, and no hooks observed; these structures are in accordance with genus Acanthobothrium ( Khalil et al., 1994) . Similar plerocercoids were recorded in the common octopus ( Octopus vulgaris ) from the Tyrrhenian Sea (Southern Italy, Central Mediterranean) with 97.95% identity match and 98% coverage of Acanthobothrium sp. from O. maya ( Tedesco et al., 2020) .

On the other hand, 94.38% identity match and 100% coverage of Acanthobothrium sp. from O. maya and Acanthobothrium sp. , larvae from the spiral intestine of Dasyatis say that was collected in Florida, USA was found ( Jensen and Bullard, 2010). Molecular data available in public databases (e. g. GenBank) showed records of the genus Acanthobothrium from the northern part of the Gulf of Mexico (Florida, Mississippi), most of them as adults and others as plerocercoid stages ( Holland et al., 2009; Jensen and Bullard, 2010). Since the parasites found in O. maya did not present genetic variation (Bt = 100) with the Acanthobothrium sp. infecting Diplectrum formosum from Mississippi ( Jensen and Bullard, 2010), it can be asserted that both specimens correspond to a similar undescribed species (As seen in Fig. 5 ).

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.

Fig. 5. Phylogenetic tree based on the Maximum Likelihood analysis of the species of the Order Trypanorhyncha found in Octopus maya constructed on partial small subunit ribosomal gene (18S) (likelihood = – 7987.787948). Bootstrap support values for ML are provided at the nodes; ex = host; the stage of development of the cestode in parentheses.