Empruthotrema stenophallus n. sp. (Monogenea: Monocotylidae) from the nasal tissue of Dasyatis kuhlii (Dasyatidae) from Sabah, Borneo, Malaysia

Empruthotrema stenophallus n. sp. (Monogenea: Monocotylidae) is described from specimens from the nasal tissue of the blue-spotted maskray Dasyatis kuhlii (Muller and Henle, 1841) collected in shallow waters off Pulau Banggi and Pulau Mabul, Sabah, Borneo, Malaysia. This is the first monogenean species to be described from an elasmobranch collected from Sabah. E. stenophallus can be distinguished from the other 6 members of the genus by the morphology of the sclerotized male copulatory organ, which is narrow, short, and distally tapered. E. dasyatidis Whittington and Kearn, 1992, previously documented from the nasal tissue of several of elasmobranch species from Australia, is recorded from 8 host species distributed around Malaysian Borneo. These represent new host and locality records for this monocotylid. The difficulties in identifying species of Empruthotrema and the apparent lack of host specificity by some members of the genus are discussed.     

Dendromonocotyle lasti n. sp. from the skin and Monocotyle caseyae n. sp. (Monogenea: Monocotylidae) from the gills of Himantura sp. (Dasyatidae) in Moreton Bay, Queensland, Australia

Seven specimens of rays of the genus Himantura which could not be identified to species were collected from waters near Dunwich, Stradbroke Island, Moreton Bay, Queensland, Australia. The five smallest specimens of Himanturasp. (disc width 218-302 mm; four female, one male) had a banded tail and the dorsal surface was uniformly grey/brown. The two largest individuals of Himantura sp. (disc widths 460, 533 mm; female and male, respectively) also had a banded tail but the grey/brown dorsal surface had white spots. Two new monogenean species (Monocotylidae: Monocotylinae) are described from both the plain and white-spotted specimens of Himantura. Dendromonocotyle lastin. sp. is distinguished from other species in the genus by the number of papillae on the haptor, by the morphology of the male copulatory organ and by the morphology of the proximal portion of the vagina. The muscular sheath which surrounds the male copulatory organ is also unique having sclerotised spines at the distal end. Dendromonocotyle species are skin parasites, but a total of five juvenile specimens of D. lasti were found on the gills of four rays. Monocotyle caseyae n. sp. from the gills is characterised by the morphology of the male copulatory organ and its accessory piece. One specimen of M. spiremae Measures, Beverley-Burton & Williams, 1990, originally described from the gills of Himantura fai Jordan & Seale off Heron Island, Great Barrier Reef, Queensland, Australia, was also found on the gills of one Himantura specimen. The site and host-specificity of the parasites and the identity of the hosts are discussed.     

Empruthotrema kearni n. sp. and observations on Thaumatocotyle pseudodasybatis Hargis, 1955 (Monogenea: Monocotylidae) from the nasal fossae of Aetobatus narinari (Batiformes: Myliobatidae) from Moreton Bay,Queensland

Empruthotrema kearni n. sp. and Thaumatocotyle pseudodasybatis Hargis, 1955 (Monogenea: Monocotylidae) are reported from the nasal fossae of the spotted eagle ray, Aetobatus narinari Euphrasen, 1790, from Moreton Bay, Queensland, Australia. The discovery of E. kearni n. sp. is the first record of this genus from the Myliobatidae and a new geographical record for the genus. A comparison of T. pseudodasybatis from Florida, USA and from Queensland, Australia revealed morphometrical and microhabitat differences. The discovery of T. pseudodasybatis in Australian waters is a new geographical record for this species.     

A new species of Monocotyle taschenberg, 1878 (Monogenea: Monocotylidae) from Dasyatis guttata (Dasyatidae)

Monocotyle guttatae n. sp. is described from the gills of the ray Dasyatis guttata (Bloch and Schneider, 1801) (Dasyatidae) off the coast of Brazil The new species can be readily differentiated from the other species of the genus in having a male copulatory organ with 2 loops and an accessory piece, 5-7 sclerites on the marginal haptoral papillae, and the absence of accessory sclerites on the dorsal surface of the posterior body. The present record confirms the presence of the genus in the subtropical waters of South America.     

Heterocotyle whittingtoni n. sp. (Monogenea: Monocotylidae) from the gills of the black-spotted whipray,Maculabatis toshi (Whitley) (Myliobatiformes: Dasyatidae), collected in coastal waters of Queensland,Australia

Heterocotyle whittingtoni n. sp. (Monogenea: Monocotylidae) is described from the gills of the black-spotted whipray Maculabatis toshi (Whitley) (Dasyatidae) collected from Moreton Bay near Dunwich and Peel Island, and from the eastern Gulf of Carpentaria off Weipa, Queensland, Australia. Heterocotyle whittingtoni n. sp. has a single sinuous ridge surmounting the haptoral septa and the male copulatory organ lacks an accessory piece. The new species can be distinguished from the two other Heterocotyle species that have this combination of characters by the distal portion of the male copulatory organ which is slightly flared with uniquely thickened walls and by the morphology of the testis. The identity of the host of H. whittingtoni n. sp. is discussed. We confirm that the host of the monocotylids Dendromonocotyle lasti Chisholm & Whittington, 2005 and Monocotyle caseyae Chisholm & Whittington, 2005 originally identified as “Himantura sp.” was M. toshi.

     

Trimusculotrema schwartzi n. sp. (Monogenea: Capsalidae) from the skin of the stingray Dasyatis zugei (Elasmobranchii: Dasyatidae) off Hong Kong,China

Trimusculotrema schwartzi n. sp. (Capsalidae) is described from the skin of the stingray Dasyatis zugei (Elasmobranchii: Rajiformes: Dasyatidae) off Hong Kong, China. Only three other species have been placed in the genus Trimusculotrema: T. micracantha (Euzet & Maillard, 1967), T. leucanthemum (Euzet & Maillard, 1967), and T. uarnaki Whittington & Barton, 1990. T. schwartzi n. sp. may be differentiated from all known species of Trimusculotrema by the length of the anterior hamuli and by the absence of pigment shields over the eye-spots. Its occurrence on a stingray off China represents a northern extension of the geographical range of Trimusculotrema.     

A new species of Thaumatocotyle (Monogenea: Monocotylidae) from Dasyatis sabina (Myliobatiformes: Dasyatidae) off the coast of South Carolina

Thaumatocotyle roumillati n. sp. is described from specimens collected in the nasal fossae of the Atlantic stingray, Dasyatis sabina (Lesueur) from the southeastern coast of the United States, off South Carolina. Thaumatocotyle roumillati is distinguished from congeners by the size and shape of its penis as well as the presence of a spinelike accessory piece associated with the penis.     

A new species of Empruthotrema (Monogenea: Monocotylidae) from Pteromylaeus bovinus (Myliobatidae) from the Western Mediterranean

Empruthotrema chisholmae n. sp. is described from specimens recovered from a bull ray Pteromylaeus bovinus (Geoffroy Saint-Hilaire, 1817) at the Oceanogràfic Aquarium in Valencia, Spain. The bull ray was caught in the Spanish Mediterranean (Puerto de Mazarrón, Murcia). The new species resembles 4 others of the same genus ( Empruthotrema dasyatidis Whittington and Kearn, 1992, Empruthotrema kearni Whittington, 1990, Empruthotrema stenophallus Chisholm and Whittington, 2005, and Empruthotrema tasmaniensis Chisholm and Whittington, 1999) in having a haptor with 13 marginal loculi, the posteriormost loculus single and medial. The new species can be distinguished from these other species of the genus by the morphology of the sclerotized male copulatory organ, which is the shortest described. The new species also differs from the other species by the following combination of features: haptor with 13 marginal loculi, the presence of eyespots, the absence of an accessory piece associated with the male copulatory organ, and a long egg appendage (more than 150 μm). Empruthotrema chisholmae is the first species of the genus reported from the Mediterranean.     

Three new species of Monocotyle (Monogenea: Monocotylidae) from the stingray, Himantura uarnak (Rajiformes: Dasyatidae) from the Great Barrier Reef: phylogenetic reconstruction, systematics and emended diagnoses

Three new species of Monocotyle were found on the gills of the coachwhip stingray, Himantura uarnak (Rajiformes: Dasyatidae) collected at Heron Island, Great Barrier Reef, Australia (23 degrees 27' S, 151 degrees 55 'E). Monocotyle helicophallus new species, Monocotyle multiparous new species and Monocotyle spiremae new species all have a single testis and are distinguished from other described Monocotyle species by size of body and hamulus and number of coils of the sclerotized male copulatory organ (21-22, three to four and 29-42, respectively). Monocotyle helicophallus new species is characterized by several muscular genital papillae, one of which is traversed by the ejaculatory duct; M. spiremae new species is distinguished by a sclerotized accessory structure associated with the distal end of the male copulatory organ, a vaginal sclerite and a conspicuous spherical, ejaculatory bulb; M. multiparous new species is distinguished by a large number of retained, thin-shelled eggs, many of which contain a fully developed oncomiracidium. A phylogenetic analysis of the 14 described species of Monocotyle utilizing 13 characters (11 binary and two multistate) produced the most parsimonious cladogram involving 18 steps with a consistency index of 0.78, two homoplasies and four unresolved polychotomies. Emended diagnoses of the Monocotylinae and Monocotyle are provided.     

Characterization of Kudoa monodactyli n. sp. (Myxosporea: Multivalvulida) from the Muscle of Monodactylus argenteus (Teleostei: Monodactylidae) from Moreton Bay, Queensland, Australia

Kudoa monodactyli n. sp. is described from the somatic musculature of Monodactylus argenteus from several localities in southern Queensland, Australia. This is the first record of a myxozoan parasite from the family Monodactylidae. The spores typically have five polar capsules, making this species similar to the four other five-valved Kudoa species (K. neurophila, K. muscularis, K. shulmani, K. cutanea) that have been described to date. However, morphometric measurements particularly of spore length and width make the species from M. argenteus distinct from the other species. Comparison of the small subunit ribosomal DNA sequence of this species with its congeners for which sequence data are available, provides further evidence of novelty. Kudoa monodactyli n. sp. displays 38 (of 1,554) nucleotide differences compared with rDNA sequence of Kudoa neurophila, which on phylogenetic analysis places these species in clades exclusive of each other. Phylogenetic analyses also provide evidence that the number of valves per spore in this genus is an imperfect indicator of relatedness.     

Septesinus gibsoni n. g., n. sp. (Monocotylidae: Heterocotylinae), from the gills of Himantura walga (Dasyatidae) off Sarawak, Borneo

Septesinus gibsoni n. g., n. sp. (Monocotylidae: Heterocotylinae) is described from the gills of the dwarf whipray Himantura walga (Müller & Henle) collected in marine waters off Sarawak (Borneo), Malaysia. Septesinus n. g. is distinguished from other genera in the Monocotylidae by a combination of characters, including a haptor with one central and seven peripheral loculi, the presence of a highly sinuous ridge surmounting all haptoral septa, four rounded accessory structures on the dorsal surface of the haptor, and the anterior region with two pairs of anteromedian and three pairs of anterolateral gland-duct openings. Septesinus n. g. is accommodated in the Heterocotylinae. Septesinus gibsoni n. sp. is described and fully illustrated, and a key to the genera of Heterocotylinae is provided. The composition of the ridges surrounding the mouth of a number of heterocotyline species and their usefulness as a taxonomic character are examined. The identity of four specimens of Monocotyle Taschenberg, 1878, also recovered from the gills of this host species, is discussed.     

Two new species of Dendromonocotyle Hargis, 1955 (Monogenea: Monocotylidae) from the skin of Taeniura meyeni (Dasyatidae) and Aetobatus narinari (Myliobatidae) from aquaria in Queensland,Australia

Dendromonocotyle pipinna n. sp. (Monogenea: Monocotylidae) is described from the dorsal skin surface of Taeniura meyeni Müller & Henle from a public aquarium in Mooloolaba, Queensland, Australia. D. torosa n. sp. was found on the dorsal skin surface of a heavily infected specimen of Aetobatus narinari (Euphrasen) during a post-mortem at the Mooloolaba aquarium and on a specimen of A. narinari kept in an aquarium in Cairns. Both of these new Dendromonocotyle species are distinguished from each other and others in the genus by the morphology of the terminal papillary sclerite and the male copulatory organ.     

A new species of Heterocotyle Scott, 1904 (Monogenea: Monocotylidae) from the gills of Dasyatis guttata (Dasyatidae) in southwestern Atlantic waters off Rio de Janeiro, Brazil

Heterocotyle sulamericana n. sp. is described from the gills of Dasyatis guttata (Bloch & Schneider) caught off the coast of Brazil near Rio de Janeiro. This species can be distinguished from all other members of Heterocotyle Scott, 1904 by a combination of the morphology of the male copulatory organ, which is a short, slightly curved, sclerotised tube with no accessory piece, and the haptor, which has a single ridge surmounting all septa. This is the first Heterocotyle species to be described from the southwestern Atlantic.     

Himantura lobistoma, a new whipray (Rajiformes: Dasyatidae) from Borneo, with comments on the status of Dasyatis microphthalmus

A new long-snouted whipray, Himantura lobistoma, is described on the basis of seven specimens collected from the southeastern sector of the South China Sea, off western Borneo. It belongs to a subgroup of Himantura species provisionally defined herein as the “uarnacoides” complex that includes five nominal species: H. chaophraya, H. granulata, H. hortlei, H. pastinacoides, and H. uarnacoides. These whiprays all have a similar lateral disc shape (i.e., pectoral-fin apices broadly rounded rather than narrowly rounded or angular), a plain colouration (i.e., usually uniform light to dark brown dorsally, and pale or whitish ventrally with or without a dark margin), a long and slender whiplike tail, and platelike denticles in a broad dorsal band in adults. Himantura lobistoma can be distinguished from the superficially similar H. hortlei by its highly protrusible mouth and pelvic girdle with prominent lateral prepelvic processes. It differs from other members of the “uarnacoides” complex by a combination of internal and external morphological characteristics (e.g., having an extremely elongate snout and very small eyes). Another long-snouted stingray from the region, Dasyatis microphthalmus Chen, inadequately described and known only from the lost holotype, is considered a nomen dubium. It had been assigned to Himantura based on the absence of an obvious ventral cutaneous tailfold but may be conspecific with D. acutirostra.     

Euzetia occultum n. g., n. sp. (Euzetiinae n. subf.), a monocotylid monogenean from the gills of Rhinoptera neglecta (Rhinopteridae) from Moreton Bay,Queensland, Australia

Euzetia occultum n. g., n. sp. (Monogenea: Monocotylidae) is described from the gills of the Australian cownose ray Rhinoptera neglecta Ogilby collected in Moreton Bay, Queensland, Australia. Euzetia has one central and ten peripheral loculi, which is similar to species in Decacotyle Young, 1967. However Euzetia is distinguished from other genera in the family by the presence of an additional loculus on either side of the central loculus. Because Euzetia does not fit into any of the six existing subfamilies in the Monocotylidae Taschenberg, 1879, as currently recognised, we propose the Euzetiinae n. subf. to accommodate the new genus. Euzetia occultum is described and illustrated fully. This is the first published record of a monocotylid from a species of Rhinoptera Cuvier.     

Monocotylids (Monogenoidea) infecting elasmobranchs in Moreton Bay,Queensland, Australia,with descriptions of Calicotyle cutmorei n. sp. (Calicotylinae) and Dendromonocotyle raiae n. sp. (Monocotylinae)

Eighteen monocotylid species were collected from elasmobranchs during surveys of the parasites of fishes of Moreton Bay, Queensland, Australia. Two new species, Calicotyle cutmorei n. sp. (Calicotylinae) from Carcharhinus sorrah (Valenciennes) (Carcharhiniformes) and Dendromonocotyle raiae n. sp. (Monocotylinae) from Hemitrygon fluviorum (Ogilby) and Neotrygon trigonoides (Castelnau) (both Myliobatiformes) are described and illustrated. Six new faunal records for Moreton Bay are reported: Thaumatocotyle australensis Beverley-Burton & Williams, 1989 (Merizocotylinae) from Maculabatis toshi (Whitley) (Myliobatiformes); Monocotyle corali Chisholm, 1998 (Monocotylinae) from Pastinachus ater (Macleay) (Myliobatiformes); Neoheterocotyle rhynchobatis (Tripathi, 1959) Chisholm, 1994 (Heterocotylinae) from Glaucostegus typus (Anonymous [Bennett]) and Aptychotrema rostrata (Shaw) (both Rhinopristiformes); and Decacotyle elpora Marie & Justine, 2005 (Decacotylinae), Dendromonocotyle torosa Chisholm & Whittington, 2004 (Monocotylinae), and Clemacotyle australis Young, 1967 (Monocotylinae) from Aetobatus ocellatus (Kuhl) (Myliobatiformes). Maculabatis toshi is a new host record for T. australensis, and A. rostrata is a new host record for N. rhynchobatis. Ten species previously recorded from Moreton Bay were collected: Monocotyle caseyae Chisholm & Whittington, 2005 (Monocotylinae) and Heterocotyle whittingtoni Chisholm & Kritsky, 2020 (Heterocotylinae) from M. toshi; Monocotyle sp. A of Chisholm (1998a) (Monocotylinae) from H. fluviorum; Dendromonocotyle kuhlii Young, 1967 and Monocotyle kuhlii Young, 1967 (both Monocotylinae) from N. trigonoides; Thaumatocotyle cf. pseudodasybatis Hargis, 1955 (Merizocotylinae), Empruthotrema kearni Whittington, 1990 (Merizocotylinae) and Decacotyle octona Young, 1967 (Decacotylinae) from A. ocellatus; and Mycteronastes icopae (Beverley-Burton & Williams, 1989) Kearn & Beverley-Burton, 1990 (Merizocotylinae) and Troglocephalus rhinobatidis Young, 1967 (Dasybatotreminae) from G. typus.

     

Chaulioleptos haywardi n. gen., n. sp. (Digenea: Sanguinicolidae) from Filimanus heptadactyla (Perciformes: Polynemidae) of Moreton Bay, Australia

Here we describe the first species of sanguinicolid blood fluke (Trematoda: Digenea) from a polynemid fish. Chaulioleptos haywardi n. gen., n. sp. is described from Filimanus heptadactyla Cuvier, 1829 (Perciformes: Polynemidae), the sevenfinger threadfin from Sandgate, Moreton Bay (southeast Queensland, Australia). Chaulioleptos haywardi differs from existing sanguinicolid genera in the combined possession of the following 7 characters: 2 testes, an entirely postovarian uterus, a uterine chamber, separate genital pores, an H-shaped intestine with abbreviated anterior caeca, tegumental spines in incomplete ventro-marginal transverse rows that are continuous along the length of the body, and vitelline follicles that are tightly compacted and subsequently appear to form a solid branching mass occupying the area anterior to intestinal bifurcation and extending posteriorly to the level of the posterior margin of the anterior testis. Chaulioleptos haywardi is most closely related to Paracardicola Martin, 1960 and Adelomyllos Nolan and Cribb, 2004.     

Calicotyle urolophi n. sp. (Monogenea: Monocotylidae) from stingarees,Urolophus spp. (Elasmobranchii: Urolophidae) taken in coastal waters of Southern Australia

Calicotyle urolophi n. sp. is proposed for calicotylines found in the cloaca of three stingaree species, Urolophus cruciatus, U. bucculentus and U. paucimaculatus, collected off the southeastern coast of Tasmania. Variations in the soft body parts were observed between specimens taken from U. cruciatus and U. bucculentus but were not considered sufficient for separation into two species. C. urolophi is differentiated from other Calicotyle spp. found in the South Pacific by the configuration of the tubular male copulatory organ, the structure of the intestinal caeca and the arrangement of the vaginae. Amended diagnoses for the subfamily Calicotylinae and the genus Calicotyle are provided.