Description of a new species of rhinebothriidean tapeworm from the skate Dipturus batis in the Mediterranean Sea

Abstract

Examination of rajid skates off the Algerian coast in the Mediterranean Sea revealed that three of the 33 Dipturus batis Linnaeus, 1758 examined harboured a new tapeworm species: Echeneibothrium algeriensis n. sp. This new species, collected from the anterior half of the spiral valves, is described on the basis of morphological data from light and scanning electron microscopy. The new species differs from previously described Echeneibothrium species by details of the scolex and loculi, total length, the length of the myzorhynchus, the number of proglottides, and the number of testes. Comparison of the diets of the ten skate species common in the Mediterranean basin indicates some varying degree of overlap, suggesting that host specificity in this host-parasite system is determined by other host and/or ecological variables such as adaptations of the parasites to their respective hosts, either on the morpho-anatomical level, in physiological characteristics of the parasite's habitat, in the trophic requirements for the successful transmission of the parasite, or in adaptations to the behavioural characteristics of the host. Furthermore, restricted overlap of E. algeriensis n. sp. with congeners in parasite assemblages of D. batis indicates some structuring according to attachment-site preferences. However, attachment-site preferences are not explained solely by morphological compatibility between bothridia and villi. This study reiterates the need to examine multiple factors synergistically in studies on host specificity of parasites, and the need to examine the parasite fauna of hosts across their entire geographical range in order to truly appreciate the biodiversity they harbour.

A holistic and comprehensive data approach validates the distribution of the critically endangered flapper skate (Dipturus intermedius)

“…comm., 2020), although there have been numerous accounts relating to D. oxyrinchus and D. nidarosiensis ( e.g ., Serena et al ., 2020). Whilst a recent parasitology‐based study has nominally reported ‘ D. batis ’ in the Mediterranean (Benmeslem et al ., 2019), the identification material used by the author pre‐dated the split in the complex, and no specific morphological information was provided, therefore this record should be considered as questionable without further means of confirmation.…”

Morphology and glandular composition of the myzorhynchus and the remnant apical organ in adult cestodes of the order Rhinebothriidea from batoids off Argentina

“…Most recent descriptions or redescriptions of cestode species commonly include the microthrix pattern observed with SEM, which is usually of taxonomic importance. Unfortunately, the microthrix pattern of the myzorhynchus of rhinebothriideans has only been studied, to our knowledge, in eight (i.e., Echeneibothrium algeriensis , E. cristinae , E. megalosoma , E. multiloculatum , E. williamsi , N. navonae , N. shetlandicum , and Pseudanthobothrium hanseni ) of the 36 species of the family Echeneibothriidae (Benmeslem et al, 2018; Bueno & Caira, 2017; Franzese et al, 2022; Ivanov & Campbell, 2002; Randhawa et al, 2008). Several of those species show a common pattern, with spinitriches restricted to the proximal portion of the myzorhynchus (i.e., AMSP) and filitriches distributed along its entire length (i.e., AMSP and AO).…”

“…megalosoma, E. multiloculatum, E. williamsi, N. navonae, N. shetlandicum, and Pseudanthobothrium hanseni) of the 36 species of the family Echeneibothriidae (Benmeslem et al, 2018;Bueno & Caira, 2017;Franzese et al, 2022;Ivanov & Campbell, 2002;Randhawa et al, 2008).…”