Derogenes abba Bouguerche & Huston & Karlsbakk & Ahmed & Holovachov 2024, n. sp.
Creators: name: Bouguerche, Chahinez
name: Huston, Daniel C.
name: Karlsbakk, Egil
name: Ahmed, Mohammed
name: Holovachov, Oleksandr
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Trematoda
Plagiorchiida
Derogenidae
Derogenes
Derogenes abba

description: Derogenes abba n. sp. (Figs. 1A–1C)
urn:lsid:zoobank.org:act: 7CB281BD-05E0-4BAF-A717- A1E4E1477AE1
Synonyms: Derogenes varicus DV 2 of Krupenko et al. [30]; D. varicus of Olson et al. [50].
Type-host: Hippoglossoides platessoides (Pleuronectiformes: Pleuronectidae), American plaice.
Type-locality: Svalbard, Norway, Arctic Ocean, at 79 59.860558 N, 15 27.879328 E, and 170 m depth.
Other hosts: Invertebrate hosts, first intermediate hosts: Amauropsis islandica (Naticidae), Iceland moonsnail; Euspira pallida (Naticidae), Pale moonsnail; Buccinum scalariforme (Buccinidae), ladder whelk (definitive host).
Other localities: United Kingdom, North Sea [50]. Keret Archipelago, White Sea. Dalniye Zelentsy, Barents Sea [30].
Site in host: Stomach.
Deposited examined material: Holotype (SMNHType-9562), 11 paratypes (SMNH- Type-9563–9573), and 2 paratypes with molecular information (hologenophores) (SMNH- Type-9563–9564) deposited in the Type collections of the Swedish Museum of Natural History (SMNH), Stockholm, Sweden. One paratype (TSZY-519) deposited in the collections of The Arctic University Museum of Norway (UiT), Tromsø, Norway.
Paratypes with molecular information: anterior parts of specimens mounted on a slide, posterior part used for molecular analysis: slide SMNH- Type-9563; slide SMNH- Type-9564.
Representative DNA sequences: Partial 28S, two sequences (GenBank, PP314018–PP314019); ITS2, two sequences (GenBank, PP314020, PP314022); Partial cox 1, two sequences (GenBank PP384389–PP384390).
Additional material examined for comparison: Whole mounts: (1) Eighteen specimens of D. varicus s. s. ex Salmo salar, Bremanger, Norway, Northeast Atlantic (SMNH 218683–218700). (2). Ten specimens of D. varicus s. s. ex Gadus morhua from Svalbard, Norway, Arctic (TSZY-520– 529). (3). Derogenes varicus s. l. from the collection of T. Odhner in the Invertebrates collection of the Swedish Museum of Natural History (SMNH): one specimen ex Limanda limanda from Gullmarsfjorden, Kristineberg, Sweden, NEA (SMNH-114551); one specimen ex Argentina sphyraena from Trondheim, Norway, NEA (SMNH-114558); one specimen ex Molva molva Trondheim, Norway, NEA (SMNH-114559); one specimen ex Brosme brosme from Trondheim, Norway, NEA (SMNH-114560); three specimens ex Hippoglossus hippoglossus from Trondheim, Norway, NEA (SMNH-104577); five specimens ex Platichthys flesus from Gullmarsfjorden, Kristineberg, Sweden, NEA (SMNH-208360).
Etymology: Named after ABBA, the Swedish pop supergroup renowned for hits like “ Dancing Queen ”, “ Chiquitita ” and “ Money, Money, Money ” which served as a source of entertainment for the first author during the creation of the illustrations. The group’ s name is an acronym of the first letters of their first names arranged as a palindrome. Invariable, treated as a noun in apposition.
Description: Measurements and comparisons in Tables 3–5. Body stocky (Figs. 1A and 1B), nearly sausage-shaped; anterior and posterior ends rounded. Pre-oral lobe short. Oral sucker rounded. Pre-pharynx absent. Pharynx muscular. Oesophagus short. Intestines bifurcating anterior to sinus-organ. Intestinal caeca extending posteriorly to vitelline masses and terminating blindly. Ventral sucker rounded.
Male terminal genitalia in forebody. Sinus-sac oval to pyriform (Figs. 1B and 1C). Cone-shaped permanent muscular sinus-organ projecting into genital atrium. Ejaculatory duct and metraterm projecting into sinus-organ. Hermaphroditic duct thin-walled. Pars prostatica relatively short, lined by gland cells, leading to seminal vesicle. Seminal vesicle voluminous, oval, and thin-walled, situated in mid-forebody at considerable distance from ventral sucker. Testes oval to globular, symmetrical, posterior to ventral sucker.
Ovary globular, voluminous, post-testicular, sometimes overlapped by right vitelline mass. Laurer’ s canal not observed. Vitelline masses in hindbody, round to oval, paired, situated on each side of body. Vitelline ducts fuse antero-medial to ovary. Seminal receptacle not observed. Uterus convoluted, uterine coils extending from near posterior extremity to sinus sac. Eggs oval. Excretory vesicle Y-shaped; branches reuniting dorsal to pharynx.
The morphology of the cercaria was described by Krupenko et al. [30].
description: Published as part of Bouguerche, Chahinez, Huston, Daniel C., Karlsbakk, Egil, Ahmed, Mohammed & Holovachov, Oleksandr, 2024, Untangling the Derogenes varicus species complex in Scandinavian waters and the Arctic: description of Derogenes abba n. sp. (Trematoda, Derogenidae) from Hippoglossoides platessoides and new host records for D. varicus (Müller, 1784) sensu stricto, pp. 1-25 in Parasite (Paris, France) (Paris, France) 31 (26) on page 6, DOI: 10.1051/parasite/2024024, http://zenodo.org/record/12524567