Escherbothriidae

Ruhnke, Timothy R., Caira, Janine N. & Cox, Allison, 2015, The cestode order Rhinebothriidea no longer family-less: A molecular phylogenetic investigation with erection of two new families and description of eight new species of Anthocephalum, Zootaxa 3904 (1), pp. 51-81 : 77

Escherbothriidae n. fam.

Diagnosis. Scolex with 4 bothridia; bothridia with or without marginal loculi; with facial loculi arranged in one or more columns at anterior of bothridia and in rows at posterior of bothridia; bothridial apical sucker present or occasionally absent; conspicuous anterior/posterior orientation of bothridia present; myzorhynchus lacking in adult stage. Postvaginal testes lacking. Vitelline follicles usually interrupted by ovary. Parasites of Myliobatiformes and Rhinopristiformes (sensu Naylor et al. 2012a).

Type genus. Escherbothrium Berman & Brooks, 1994 . Additional genera: New Genus 3 of Healy et al. (2009) and Caira et al. (2014).

Remarks. The genus Escherbothrium is included here for the first time in a molecular analysis. While this monotypic genus was originally described by Berman & Brooks (1994) from Urotrygon chilensis (Günther) our specimen came from Urotrygon aspidura and appears to represent a second, as-of-yet undescribed, member of the genus. Nonetheless, this species grouped relatively robustly with the eight species of New Genus 3 (of Healy et al. 2009) included in our analyses. As the latter genus is known in published literature only from molecular data (i.e., New genus 3 of Healy et al. 2009 and Caira et al. 2014) and has not yet been formally described, the morphological information of Healy (2006) for several species (figs. 1.27–1.30) was used to generate the diagnosis of the family presented here. The most problematic element of the diagnosis is whether all species possess an apical sucker. Both Escherbothrium molinae Berman & Brooks 1994 and the new species of Escherbothrium exhibit a conspicuous apical sucker on each bothridium. The presence of this feature in E. molinae was treated in detail by Berman & Brooks (1994) and it is clearly visible on the undescribed species of Escherbothrium included here (LRP 8519). In both species the apical sucker is located on the anterior margin of a single apical loculus and this loculus is followed by a row of four loculi. However, only some of Healy’s (2006) illustrations of New Genus 3 show a feature that could be interpreted as an apical sucker. Thus, the presence of an apical sucker remains to be confirmed in the formal descriptions of species of New Genus 3. Escherbothriidae n. fam. is easily distinguished from the Echeneibothriidae in its lack of a myzorhynchus in adult worms and from the Rhinebothriidae in possessing a clear anterior/posterior orientation to its bothridia signaled by a conspicuous apical sucker and/or an anterior column of facial loculi. It most closely resembles the Anthocephaliidae but differs in that its bothridia bear facial loculi that are arranged in columns anteriorly and rows posteriorly, rather than in multiple rows or entirely lacking.