Dichelyne (Cucullanellus) romani n. sp. (Nematoda: Cucullanidae) in notacanthid fishes from the Northeast Atlantic and Western Mediterranean

Abstract

A new cucullanid, Dichelyne (Cucullanellus) romani n. sp. (Nematoda: Cucullanidae), is described from the digestive tract of two notacanthid fishes, Notacanthus chemnitzii Bloch and N. bonaparte Risso (Notacanthiformes: Notacanthidae), from the Northeast Atlantic and Western Mediterranean. The presence of a precloacal sucker and ten pairs of caudal papillae in males allocates it to the subgenus Cucullanellus Törnquist, 1931. The new species differs from other members of this subgenus in its larger body size, smaller spicule/body length ratio, the distribution of caudal papillae, and the position of deirids and excretory pore. Both notacanthid fishes act as definitive hosts with slightly larger nematode specimens detected in N. chemnitzii. A wide intraspecific variability was found in the distribution of caudal papillae, and in some specimens the position of deirids, excretory pore and length of intestinal caecum also varied. A complete list of all assigned species of the subgenus Cucullanellus is presented and discussed as there are several uncertainties regarding the validity and synonymy of some species. This is the first species of Dichelyne Jägerskiöld, 1902 in a notacanthid fish and one of the only two records in deep-sea fish species.

Raphidascaris ( Raphidascaris ) macrouri n. sp. (Nematoda: Anisakidae) from two deep-sea macrourid fishes in the Western Mediterranean: Morphological and molecular characterisations

“…This difference may be related to the host size (T. scabrus is bigger than N. aequalis). The influence of the host size on the total length of parasites has already been reported in nematodes of freshwater and marine fishes [33][34][35][36]. Interestingly, the disposition of the vagina also varied among the gravid females of the new species.…”

First Record of Dichelyne (Cucullanellus) tripapillatus (Nematoda: Cucullanidae) Parasitic in King Soldier Bream Argyrops spinifer (Pisces: Sparidae) in Arabian Gulf, off Iraq

“…The present specimens are included within the subgenus Cucullanellus due to the possessing of precloacal ventral sucker and 10 pairs of papillae, the first pair being close to the ventral sucker. Isbert et al (2015) presented the species of Dichelyne (Cucullanellus) with the families of their hosts and the original geographical locations; three species were recorded as parasites of Sparidae. These were D. (C.) adriaticus (Törnquist, 1931) in the gilthead seabream Sparus aurata from the Mediterranean Sea off the Italian coast, D. (C.) jialaris Luo, Guo, Fang & Hang, 2004 The morphological characters of the current nematode agreed with the description of D. (C.) tripapillatus, which was historically recorded from three species of sparids excluded type host, Sepiola rondeleti (=Pagrus auratus), Chysophrys aurata (=Sparus aurata) and Chaetodon bifasciatus (=Acanthopagrus bifasciatus) (Ivashkin & Khromova, 1976) and from Diplodus sargus (Sparidae) in the Adriatic Sea off the coast of Montenegro by Petter & Radajković (1989).…”

“…Terminology related to measurements associated with the male ventral sucker varied between various global studies; from the beginning of the sucker to the end of tail (Isbert et al, 2015), mid-sucker to end of tail (Luo et al, 2004), mid-sucker to the beginning of the cloaca (Li et al, 2014) or without giving importance to this character (Moravec et al, 2018).…”

First record of Dichelyne (Dichelyne) bonacii (Nematoda, Cucullanidae) parasitizing the intestine of two species of lutjanid fish (Perciformes, Lutjanidae) on the northeast Brazilian coast

“…The characteristics previously described, especially in relation to the instestine with 2 intestinal cecums, to the arrangement of caudal papillae and the absence of a ventral "sucker", allowed identification as D. bonacii. Five other species of the genus Dychelyne have been described in the gut of other fish of families such as Sciaenidae, gobiidae, Haemulidae, Pleuronectidae, Serranidae and lutjanidae, in localites as Argentina, New Caledonia (Southern Pacific Ocean), China (guangdong Province and region leste), Iran (Persian gulf), Southeastern Brazil (Coast of Rio de Janeiro), Northeast Atlantic, Western Mediterranean and South America (Atlantic Coast) (Timi et al 2009, Moravec and Justine 2011, li et al 2014a, b, Moravec et al 2014, Paschoal et al 2014, Isbert et al 2015.…”