Sciadicleithrum Kritsky, Thatcher & Boeger 1989
Creators: name: Bellay, Sybelle
name: Takemoto, Ricardo Massato
name: Yamada, Fábio Hideki
name: Pavanelli, Gilberto Cezar
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Trematoda
Monopisthocotylea
Dactylogyridae
Sciadicleithrum

description: Sciadicleithrum Kritsky, Thatcher & Boeger, 1989
Type-species: Sciadicleithrum uncinatum Kritsky, Thatcher & Boeger, 1989 from Cichla ocellaris Bloch & Schneider.
Others species: Sciadicleithrum tortrix Kritsky, Thatcher & Boeger, 1989 from Uaru amphiacanthoides Heckel; Sciadicleithrum umbilicum Kritsky, Thatcher & Boeger, 1989 and Sciadicleithrum ergensi Kritsky, Thatcher & Boeger, 1989 from Cichla ocellaris Bloch & Schneider; Sciadicleithrum geophagi Kritsky, Thatcher & Boeger 1989 from Geophagus surinamensis (Bloch); Sciadicleithrum iphthimum Kritsky, Thatcher & Boeger 1989 from Pterophyllum scalare (Lichtenstein); Sciadicleithrum aequidens (Price & Schlueter, 1967) Kritsky, Thatcher & Boeger, 1989 from Aequidens maroni (Steindachner); Sciadicleithrum cavanaughi (Price, 1966) Kritsky, Thatcher & Boeger, 1989 from Aequidens maroni (Steindachner); Sciadicleithrum variabilum (Mizelle & Kritsky, 1969) Kritsky, Thatcher & Boeger, 1989 from Symphysodon discus Heckel; Sciadicleithrum mexicanum Kritsky, Vidal-Martínez & Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther), Cichlasoma trimaculatum (Günther), Parachromis dovii (Günther), Parachromis managuense (Günther), Tomocichla tuba (Meek), Vieja maculicauda (= Cichlasoma maculicauda) (Regan), Vieja synspila (= Cichlasoma synspilum)(Hubbs), Rocio octofasciata (= Cichlasoma octofasciatum) (Regan), Parachromis friedchstahlii (Heckel), Petenia splendida Günther, Theraps aureus (= Cichlasoma aureum)(Günther); Sciadicleithrum bravohollisae Kritsky, Vidal-Martínez & Rodriguez-Canul, 1994 from Cichlasoma pearsei (Hubbs), Vieja synspila (Hubbs), Petenia splendida Günther, Vieja fenestrata (Günther), Vieja maculicauda (Regan), Theraps lentiginosus (Steindachner), Cichlasoma salvini (Günther), Cichlasoma geddesi (Regan), Parachromis managuensis (Günther); Sciadicleithrum splendidae Kritsky, Vidal-Martínez & Rodriguez-Canul, 1994 from Petenia splendida Günther and Parachromis friedrichstahlii (Heckel); Sciadicleithrum meekii Mendoza-Franco, Scholz & Vidal-Martínez, 1997 from Thorichthys meekii (= Cichlasoma meeki) (Brind), Amatitlania nigrofasciata (= Archocentrus nigrofasciatus) (Günther), Thorichthys callolepis (Regan), Thorichthys helleri (Steindachner); Sciadicleithrum maculicaudae Vidal- Martínez, Scholz & Aguirre-Macedo, 2001 from Vieja maculicauda (Regan); Sciadicleithrum nicaraguense Vidal-Martínez, Scholz & Aguirre-Macedo, 2001 from Amphilophus alfari (Meek); Sciadicleithrum bicuense Vidal-Martínez, Scholz & Aguirre-Macedo, 2001 from Amatitlania nigrofasciata (Günther); Sciadicleithrum panamensis Mendoza-Franco, Aguirre-Macedo & Vidal-Martínez, 2007 from Aequidens coeruleopunctatus (Kner); Sciadicleithrum frequens Bellay, Takemoto, Yamada & Pavanelli, 2008 and Sciadicleithrum guanduensis Carvalho, Tavares & Luque, 2008 from Geophagus brasiliensis (Quoy & Gaimard); Sciadicleithrum joanae Yamada, Takemoto, Bellay & Pavanelli, 2009 from Crenicichla niederleinii (Holmberg) and Crenicichla britskii Kullander; and Sciadicleithrum satanopercae Yamada, Takemoto, Bellay & Pavanelli, 2009 from Satanoperca pappaterra (Heckel).
Emended diagnosis: Body divisible into cephalic region, trunk, peduncle, haptor. Tegument thin, smooth. Mouth subterminal, midventral; pharynx muscular, glandular; oesophagus present; intestinal ceca 2, confluent posteriorly, lacking diverticula. Four pair of head organs; 2 terminal, 2 bilateral cephalic lobes; unicellular cephalic glands composed of 2 groups posterolateral to pharynx. Eyes present; accessory granules. Gonads overlapping or slightly overlapping, intercecal, testis dorsal to ovary. Vas deferens looping around left intestinal cecum, seminal vesicle a dilation of vas deferens; 1 or 2 prostatic reservoirs. Male copulatory organ (MCO) composed of a base from which a coiled tube arises, a clockwise or counterclockwise coil of about less than 1 to more than 2 rings. Accessory piece present. Genital pore midventral at level of intestinal bifurcation. Oviduct short; uterus delicate, extending anteriorly along midline; seminal receptacle ventral to anterior end of ovary; vagina sinistral, dextral, or ventral. Vitelline follicles well developed, scattered throughout trunk. Haptor armed with dorsal and ventral pairs of unmodified anchors, ventral and dorsal bars, 7 pairs of similar hooks with ancyrocephaline distribution. Longitudinal lateral grooves on the shafts and points of ventral and dorsal anchors present or absent; hook shanks slender, thumb erect, variation in size present or absent; ventral bar with 1 or 2 variably developed umbelliform membranes or cavities on anterior bar margin; medial projection in bars present or absent; dorsal bar with umbelliform membranes present or absent. Parasites of gills of Neotropical Cichlidae (Perciformes).
Remarks: When Sciadicleithrum was erected, six species were described (S. uncinatum, S. tortrix, S. umbilicum, S. ergensi, S. geophagi, S. iphthimum), and three species were presented as new combinations (S. aequidens, S. cavanaughi, S. variabilum) later another 12 species were described, which introduced characteristics not used in the original description of the genus: gonads slightly overlapping (S. bravohollisae, S. cavanaughi, S. mexicanum, S. splendidae), ventral bar with umbelliform membrane unique (S. guanduensis), longitudinal lateral grooves on the shafts and points of ventral and dorsal anchors (S. bravohollisae, S. maculicaudae, S. mexicanum, S. nicaraguense, S. splendidae, S. frequens), variation in the size of the hooks pairs (S. frequens, S. satanopercae), dorsal bar with umbelliform membranes (S. nicaraguense, S. joanae), medial projection in bars (S. meekii), and MCO with more 2 rings (S. meekii, S. splendidae, S. tortrix, S. satanopercae) (Mendoza-Franco & Vidal-Martínez 2005; Mendoza-Franco et al. 2007; Bellay et al. 2008; Carvalho et al. 2008; Yamada et al. 2009). Although presence of a posteromedial projection in the ventral bar of S. meekii was not mentioned in the original description, Vidal-Martínez et al. 2001 illustrated this feature.
description: Published as part of Bellay, Sybelle, Takemoto, Ricardo Massato, Yamada, Fábio Hideki & Pavanelli, Gilberto Cezar, 2009, Two new species of Sciadicleithrum (Monogenea: Dactylogyridae), gill parasites of Geophagus proximus (Castelnau) (Teleostei: Cichlidae), from the upper Paraná River floodplain, Brazil, pp. 57-66 in Zootaxa 2081 on pages 58-59, DOI: 10.5281/zenodo.187358