The genus Deretrema Linton, 1910 (Digenea: Zoogonidae) from southern Great Barrier Reef fishes,with a description of Deretrema woolcockae n. sp.

Two species of Deretrema (Zoogonidae) are reported from labrid fishes from the Great Barrier Reef. D. nahaense Yamaguti, 1942 is recorded from the gall-bladders of the labrids Thalassoma hardwicke (Bennett), T. jansenii (Bleeker), T. lunare (Linnaeus) and T. lutescens (Lay & Bennett). This species is recognised, despite having been formerly synonymised with D. pacificum Yamaguti, 1942. In addition to morphological distinction, D. nahaense appears to have strict host-specificity for the genus Thalassoma. D. woolcockae n.sp. is described from the gallbladder of Hemigymnus fasciatus (Bloch). The new species is close to D. acutum Pritchard, 1963 and D. plotosi Yamaguti, 1940, but differs slightly in the distribution of the vitelline follicles, the sucker-ratio and the position of the cirrus-sac. In addition, this species also appears to have a distinct host-specificity, being restricted to one labrid species.     

Overstreetia olsoni n. sp. (Digenea: Zoogonidae) from the Capricorn silverside Atherinomorus capricornensis (Woodland) (Atherinidae) off Heron Island, southern Great Barrier Reef

A new species, Overstreetia olsoni, is described from Atherinomorus capricornensis off Heron Island on the Great Barrier Reef off Queensland, Australia. It differs from its only known congener in that the enlarged spines of the circum-oral rows are smaller ( ≤ 4.5 × 3.5 vs ≤ 21.5 × 10.5μm), the sucker-ratio is smaller (1: 0.97–1.01 vs 1:1.8) and the eggs are larger (40–45 × 22–28 vs 34–37 × 17–22μm).     

Steganoderma (Steganoderma) valchetensis n. sp. (Digenea: Zoogonidae) from the relict fish Gymnocharacinus bergi (Osteichthyes: Characidae) in Argentina

A new species of Steganoderma (Steganoderma) (Digenea: Zoogonidae) was found in the digestive tract of the southernmost, endemic and scale-less characid, Gymnocharacinus bergi, inhabiting thermal headwaters of the Valcheta Creek in northern Patagonia, Argentina. Steganoderma valchetensis n. sp. is included in the subgenus Steganoderma because of having a sessile ventral sucker and caeca reaching to the testes. This new species can be distinguished from other species of this genus on the basis of body-length, sucker-ratio, the length of the cirrus-sac, the morphology of the seminal vesicle and gonads, and the location of the vitelline follicles and genital pore. The taxonomic status of the species of Steganoderma, parasitising the freshwater fishes of Patagonia, in southern Argentina, and Chile, is also discussed.     

Preptetos cannoni n. sp. (Digenea: Lepocreadiidae) from Siganus lineatus (Teleostei: Siganidae) from the southern Great Barrier Reef,Australia

Preptetos cannoni n. sp. is described from Siganus lineatus from Heron Island on the southern Great Barrier Reef, Australia. Morphological features that are diagnostic of this species include: a genital pore that is sinistral to the ventral sucker and vitelline follicles that reach anteriorly to at least the bifurcation of the intestine. This is the first report of a species of the genus Preptetos from Australian waters and from fishes of the genus Siganus.     

Hemiuridae (Digenea) from marine fishes of the Great Barrier Reef,Queensland, Australia

The following species are described, figured and/or recorded from the Great Barrier Reef at Heron Island or Lizard Island, Queensland, with comparative material reported from other areas of the ocean around Australia or New Guinea: Dinurus longisinus (new synonym: D. hippuri) from Seriola lalandi, Heron Island and Coryphaena hippurus, Papua New Guinea; Ectenurus trachuri from Caranx sexfasciatus, Diploprion bifasciatus, Pterocaesio marri, Seriola lalandi and Atherinomorus capricorniensis, Heron Island; Erilepturus hamati (with 25 new synonyms) from Lutjanus carponotatus, Lizard Island, Platycephalus bassensis, Coff's Harbour, NSW, P. fuscus, Coff's Harbour, NSW and Moreton Bay, Queensland, P. endrachtensis, Sillago analis, S. maculata, S. ciliata, Pseudorhombus arsius and Polydactylus sp. from Moreton Bay, Queensland and Lates calcarifer, Darwin, Northern Territory; Tubulovesicula angusticauda from Echeneis naucrates and Lethrinus miniatus, Heron Island and Anguilla reinhardtii, Moreton Bay and Bribie Island, Queensland; Elytrophalloides humerus from Trachinotus botla and T. coppingeri, Heron Island; Lecithochirium kawakawa from Euthynnus affinis Heron Island and Lizard Island: Lecithochirium cirrhiti (new synonyms: L. sammarae, L. nohu) from Sargocentron rubrum, Heron Island; Lecithochirium caesionis from Pterocaesio marri, heron Island; Plerurus digitatus (new synonyms: P. cynoglossi, P. atulis, P. scomberomori) from Plectropomus leopardus, Heron Island, Lutjanus erythropterus, Variola louti, Scomberomorus semifasciatus, Grammatorcynus bicarinatus and Carangoides embureyi, C. gymnostethoides, Lizard Island, Scomberomorus commerson, Heron Island, Lizard Island, New Britain, Papua New Guinea, Point Lookout, Queensland and Moreton Bay, Queensland, Euthynnus affinis Heron Island, Lizard Island and New Britain, Papua New Guinea, Sphyraena barracuda, Heron Island and Lizard Island, Scomberomorus munroi, S. queenslandicus and Saurida undosquamis, Moreton Bay, Queensland and Chirocentrus dorab, Bundaberg, Queensland. The Lecithochirium species-group Cirrhiti is considered indistiguishable from the species-group Lotellae.     

Two Lepotrema Ozaki, 1932 species (Digenea: Lepocreadiidae) from marine fishes from the southern Great Barrier Reef, Queensland, Australia

The genus Lepotrema Ozaki, 1932 is revived and redefined. Its main diagnostic characters are the dorsal excretory pore, the muscular development of the distal metraterm and the trilobate ovary. It is considered to contain five species, to which a key is given. Lepotrema clavatum Ozaki, 1932 is briefly redescribed from Amanses scopas and Sufflamen chrysopterus, and L. canthescheni n. sp. is described from Cantheschenia grandisquamis, based on material from the southern Great Barrier Reef. L. canthescheni is distinguished by its vitelline and uterine distribution. The other three recognised species are: L. adlardi (Bray, Cribb & Barker, 1993) n. comb., L. incisum (Hanson, 1955) n. comb. and L. xanthichthydis (Yamaguti, 1970) n. comb., all three having originally been placed in Lepocreadium.     

The life-cycle of Helicometra gibsoni n. sp. (Digenea: Opecoelidae)

The life-cycle of Helicometra gibsoni n. sp., an opecoelid trematode of marine fishes, is elucidated and the life-history stages are described. Natural infections with the cercariae, which are typically opecoelid in many respects but characterised by having very long, extensile tails, were found in the intertidal snail Anachis terpsichore collected from the Lawson's Bay Coast, Bay of Bengal. Metacercariae were found in the thoracic muscles of the shooting shrimp Alphaeus malabaricus as prominent, reddish-brown, oval cysts. Laboratory experiments demonstrated that 14 days are required for the development of cercaria into the infective metacercarial stage in shrimps. Natural infections with the adult fluke were found in Scorpaenopsis cirrhosus. Therapon jarbua served as an experimental host. Fourteen-day-old metacercariae fed to T. jarbua developed into egg-producing adults in 40–43 days. Intra-specific variations noted in the flukes obtained from natural and experimental infections are presented. H. fasciata of Madhavi (1975) is regarded as a synonym of H. gibsoni.     

A new macradeninine,Zebrasomatrema pichelinae n. g., n. sp. (Digenea: Lecithasteridae), from tangs (Perciformes: Acanthuridae) off the southern Great Barrier Reef,Queensland, Australia

A new genus, Zebrasomatrema, with the type-species Z. pichelinae n. sp., is described from Zebrasoma veliferum at Heron and Lizard Islands, Queensland, Australia, and Z. scopas, Acanthurus lineatus and A. triostegus at Heron Island. The new genus shares with Acanthurotrema an anterior flange, 14 subglobular vitelline lobes, a divided seminal vesicle and a long aglandular duct joining the seminal vesicle and the short pars prostatica, but differs in its quadripartite seminal vesicle, single vitelline field, lack of a sinus-sac and excretory arms which unite in the forebody. This report constitutes the first record of a macradeninine lecithasterid in Australian waters. A key to the Macradenininae is presented.     

Four species of Lepidapedoides Yamaguti, 1970 (Digenea: Lepocreadiidae) from fishes of the southern Great Barrier Reef, with a tabulation of host-parasite data on the group

Four species of the genus Lepidapedoides Yamaguti, 1970 are described from Heron Island, southern Great Barrier Reef, Queensland, Australia. They are: Lepidapedoides angustus n. sp. in Epinephelus fasciatus (type-host), E. cyanopodus, E. merra, E. quoyanus, E. ongus, Cephalopholis miniata and Diploprion bifasciatum; L. dollfusi (Durio & Manter, 1968) n. comb. [originally Neolepidapedon] in Epinephelus cyanopodus; L. ovale (Yamaguti, 1942) n. comb. [originally Pseudocreadium] in Caesio cuning and Pterocaesio marri; and L. parvulus n. sp. in Pterocaesio marri (type-host) and Caesio cuning. Host and distribution information on the species of the genus are tabulated according to morphological group. Mycterobonacinus Nasir & Gomez, 1977 is considered synonymous with Lepidapedoides, and M. magnifus is considered a synonym of L. nicolli.     

Steganoderma szidati n. sp. (Trematoda: Zoogonidae) from Galaxias maculatus (Jenyns) and G. platei Steindachner in Patagonia,Argentina

Steganoderma szidati n. sp. is described from the intestine of two freshwater fishes, Galaxias maculatus and G. platei (Galaxiidae), from Andean lakes in Patagonia, Argentina. This freshwater zoogonid species fits in the genus Steganoderma (sensu Bray, 1987) because of the length of the caeca and the position of the vitelline follicles. The new species is characterised by possesing 6-13 vitelline follicles situated between the anterior margin of the ventral sucker and the poterior margin of the testis. The gonads are in the anterior hindbody and the ovary is anterior to the right testis. The cirrus has two conspicuous spines at its distal end, and the seminal vesicle always exhibits a constriction. The excretory vesicle never reaches the level of the posterior margin of the testes.     

Taxonomy, host specificity and dietary implications of Hurleytrematoides (Digenea: Monorchiidae) from chaetodontid fishes on the Great Barrier Reef

Five new and five previously described species of Hurleytrematoides are reported from 19 of 34 chaetodontid species examined from the Great Barrier Reef; new species are H. faliexae n. sp., H. galzini n. sp., H. loi n. sp., H. morandi n. sp., and H. sasali n. sp. Previously described species are H. coronatum, H. fijiensis, H. prevoti, H. bartolii, and H. zebrasomae. The genus is rediagnosed in the light of morphological variation of the new species; the degree of spination and shape of the terminal genitalia distinguish individual species. Species of Hurleytrematoides infect almost every clade of the family Chaetodontidae found on the Great Barrier Reef, but obligate corallivores are not infected. All ten species were found at Heron Island on the southern Great Barrier Reef, but only six at Lizard Island on the northern Great Barrier Reef. For three of the four species not present at Lizard Island, the absence appears to be statistically significant. Although all species are apparently restricted to chaetodontids on the GBR, specificity within the family varies from oioxenous to euryxenous; a core/satellite host paradigm explains the distribution of several species.     

Postlepidapedon Zdzitowiecki, 1993 and Gibsonivermis n. g. (Digenea: Lepocreadiidae) from fishes of the southern Great Barrier Reef, Australia, and their relationship to Intusatrium Durio & Manter, 1968

The genus Intusatrium Durio & Manter, 1968 is redefined based on a re-examination of paratypes of the type-species, I. robustum Durio & Manter, 1968, and is considered monotypic with characteristic terminal genitalia: internal seminal vesicle elongate tubular, with rather thick wall, divided by slight change in wall thickness into longer proximal and shorter distal region; pars prostatica subcylindrical; ejaculatory duct relatively short, with wrinkled/wall. The genus Postlepidapedon Zdzitowiecki, 1993 is redefined and Intusatrium secundum Durio & Manter, 1968 is attributed to it as a new combination. Postlepidapedon secundum n. comb. is redescribed from a paratype and new material from Choerodon graphicus. P. spissum n. sp. from Choerodon venustus, C. cyanodus, C. fasciatus and C. schoenleinii is recognised on the basis of its thick-walled internal seminal vesicle. P. uberis n. sp. from Choerodon schoenleinii and C. venustus is distinguished by the shape and contents of the cirrus-sac with narrow, convoluted internal seminal vesicle, large vesicular pars prostatica and short, muscular ejaculatory duct. A new genus, Gibsonivermis, erected for Intusatrium berryi Gibson, 1987, is characterised by the elongate narrow cirrus-sac and a uroproct. G. berryi n. comb. is redescribed from Sillago ciliata, S. maculata and Sillago sp.     

Dactylomyza gibsoni n. g., n. sp. (Digenea: Opecoelidae) from Schuettea woodwardi (Waite) (Monodactylidae) from off Western Australia

An opecoelid digenean, Dactylomyza gibsoni n. g., n. sp. is described and figured from Schuettea woodwardi (Waite), a monodactylid from off the coast of Western Australia. The new genus conforms to the concept of the opecoelid subfamily Opecoelinae. The resemblance of the new genus to three other opecoelid genera, Pseudopecoeloides Yamaguti, 1940, Opecoeloides Odhner, 1928 and Poracanthium Dollfus, 1948, is discussed. Dactylomyza n. g. is distinguished from these morphologically similar worms on the basis of its median genital pore, ventral sucker appendages, uroproct and the absence of an accessory sucker. Pseudopecoeloides equesi Manter, 1947 is transferred to the new genus as Dactylomyza equesi (Manter, 1947) n. comb.     

Reproductive biology of bisexual and all-female populations of chaetodontid fishes from the southern Great Barrier Reef

Synopsis The reproductive biology of three species of chaetodonts from One Tree Reef (southern GBR) is described by analysis of gonads and population structure. Reproductive biology is related to age by a capture-markrecapture study of growth. For Chaetodon rainfordi there was a significant habitat effect. On the reef slope, females outnumbered males by 5.6: 1 and both sexes became reproductively active by the age of 2 years. In the lagoon, no males were found and females were reproductively inactive. For C. plebius, males were essentially missing from all samples and no reproductively active females were found. For Chelmon rostratus (1 :1 sex ratio) some males had mature testes but there was no evidence of female reproductive activity. This species is likely to be gonochoristic, but the reproductive mode of the other two species remains ambiguous.     

Proctophantastes brayi, n. sp. (Digenea: Zoogonidae) parasite of the deep-sea fish Polymixia Lowe, 1838 from Vanuatu

Proctophantastes brayi n. sp. (Digenea: Zoogonidae; Lepidophyllinae) has been found in the intestine of two species of deep-sea fish Polymixia (silver eye fish) near the island of Erromango in Vanuatu at a depth ranging from 720 to 830 m. Specimen whole mounts, histological and scanning electron microscopy preparations showed that P. brayi differs from the five known species of the genus Proctophantastes (P. abyssorum, P. gillissi, P. glandulosum, P. infundibulum and P. nettastomatis) by the following morphological characters: (i) a slit in the anterior part of the oral sucker, (ii) Laurer's canal is absent, (iii) a more extended periatrial gland than the ones in the other species of Proctophantastes, consisting of divided masses of cells and that form a conspicuous multilobated structure which does not have a membrane-bounded sac, (iv) the distal part of the metraterm has vesicle-like processes which we refer to as metratermal sacs, in addition to atrial sacs, (v) a long extension of the glandular cells surrounding the saccular bladder which extends posteriorly to the excretory pore.     

Lepocreadiidae (Digenea) from the batfish of the genus Platax Cuvier (Teleostei: Ephippidae) from the southern Great Barrier Reef,Queensland, Australia

The following species are described from Platax spp.: Neomultitestis aspidogastriformis n. sp., from P. teira, off Heron Island, Queensland, which can be distinguished from its congeners by the transversely elongate ventral sucker divided into three loculi and probably by testis number; Multitestis magnacetabulum Mamaev, 1970, from P. teira, off Heron Island, Queensland; Diploproctodaeum rutellum (Mamaev, 1970), from P. teira, off Heron Island, Queensland; Diploproctodaeum tsubameuo n. sp., from P. batavianus, from the Swain Reefs, off Queensland, which differs from its congeners in its overlapping, posteriorly attenuated testes and 38-55 ovarian lobes; and Diplocreadium sp., from P. batavianus, from the Swain Reefs, off Queensland.