Two new genera, Provitellus and Ovipusillus, and four new species of Monorchiidae (Digenea) from carangid fishes of queensland, Australia

Two new genera and four new species of monorchiid digeneans are described from the Great Barrier Reef and Moreton Bay, Queensland. Provitellus turrum n. g., n. sp. from Pseudocaranx dentex and Trachinotus coppingeri is characterised by the presence of vitelline follicles in the forebody, a single testis, a unipartite terminal organ and filamented eggs. Ovipusillus mayu n. g., n. sp. from Gnathanodon speciosus is characterised by the presence of two testes, vitelline follicles overlapping the ventral sucker and a large, complex cirrus-sac that contains a coiled eversible ejaculatory duct joined by the pars prostatica halfway along its length. Paramonorcheides pseudocaranxi n. sp. from Pseudocaranx dentex differs from other species described in this genus in the longer flatter forebody, entire ovary and the well-developed cirrus-sac. Chrisomon gaigai n. sp. from Trachinotus coppingeri and T botla is characterised by the unflattened forebody and transversely oval pharynx. Chrisomon is redefined to include species of Lasiotocus with a vitellarium composed of clusters of tubular acini, creating the following new combinations: C. albulae n. comb. for L. albulae Overstreet, 1969, C. ulua n. comb, for L. ulua Yamaguti, 1970 and C. weke n. comb, for L. weke Yamaguti, 1970. The diagnosis of Lasiotocus is amended accordingly and the new combinations, L. polynemi n. comb. and L. sunderbanensis n. comb., are created for C.polynemi Dutta, Hafeezullah & Manna, 1994 and C. sunderbanensis Dutta, Hafeezullah B Manna, 1994, respectively. Extrapolation of our collection data suggests that there may be as many as 80 species of monorchiids infecting carangid fishes in Australia and 180 species infecting carangids in all oceans of the world. The latter figure greatly exceeds the number of monorchiids described from all host families to date.

Lepocreadiidae (Digenea) of Australian coastal fishes: new species of Opechona Looss, 1907, Lepotrema Ozaki, 1932 and Bianium Stunkard, 1930 and comments on other species reported for the first time or poorly known in Australian waters

Opechona austrobacillaris n, sp. is described from Pomatomus saltatrix from marine sites off Western Australia and New South Wales, Australia. It differs from O. bacillaris in its elongate outline, small ventral sucker, longer pseudoesophagus (relative to the oesophagus), relatively shorter ventral sucker to ovary distance and the relatively longer post-testicular region. Lepotrema monile n. sp. is described from Pomacentrus wardi from Heron Island, Queensland. It differs from its congeners in the sphincter around the distal metraterm and the more-or-less oval ovary. Bianium spongiosum n. sp, is described from Ostracion cubicus from Lizard Island, Queensland. It differs from its congeners in lacking lateral flaps in the forebody, but in having large, internal spongiform patches in the lateral forebody. The following species are redescribed from Australian sites: Lepocreadium oyabitcha from Abudefduf whitleyi, Lizard Island; Clavogalea trachinoti from Trachinotus botla, Heron Island and T. coppingeri, New South Wales, Stradbroke Island, Queensland and Heron Island; Myzoxenus insolens from Notolabrus parilus, Western Australia; Bulbocirrus aulostomi from Aulostomus chinensis, Heron Island; Lepocreadioides orientalis [new synonyms: Bicaudum interruptum Bilqees, 1973; Lepocreadioides interruptum (Bilqees, 1973) Madhavi, Narasimhulu & Shameem, 1986; Lepocreadioides discum Wang, 1986; Lepocreadioides sp. of Karyakarte & Yadav (1976)] from Cynoglossus bilineata, Moreton Bay, Queensland; Hypocreadium patellare from Sufflamen chrysopterus, Heron Island; Echeneidocoelium indicum from Echeneis naucrates, Heron Island; Multitestis pyriformis from Epinephelus cyanopodus, Heron Island; Pseudopisthogonoporus vitellosus from Naso brevirostris, Heron Island; and Bianium hispidum from Torquigener whitleyi and T. pleurogramma, southern Queensland. Only M. solens and M. pyriformis have been reported from Australian waters before; both are new host records.

Muscle fibre types and size distribution in sub-antarctic notothenioid fishes

The presumptive tonic muscles fibres of Cottoperca gobio, Champsocephalus esox, Harpagifer bispinis, Eleginops maclovinus, Patagonothen tessellata, P. cornucola and Paranotothenia magellanica stained weakly or were unstained for glycogen, lipid, succinic dehydrogenase (SDHase) and myosin ATPase (mATPase) activity. Slow, intermediate and fast twitch muscle fibres, distinguished on the basis of the pH stability of their mATPases, showed intense, moderate and low staining activity for SDHase, respectively. Slow fibres were the major component of the pectoral fin adductor profundis muscle. The proportion of different muscle fibre types varied from the proximal to distal end of the muscle, but showed relatively little variation between species. The myotomes contained a lateral superficial strip of red muscle composed of presumptive tonic, slow twitch and intermediate fibres, thickening to a major wedge at the horizontal septum. All species also had characteristic secondary dorsal and ventral wedges of red muscle. The relative abundance and localization of muscle fibre types in the red muscle varied between species and with body size in the protandric hermaphrodite E. maclovinus. The frequency distribution of diameters for fast twitch muscle fibres, the major component of deep white muscle, was determined in fish of a range of body sizes. The absence of fibres <20 mu m diameter was used as a criterion for the cessation of muscle fibre recruitment. Fibre recruitment had stopped in P, tessellata of 13.8 cm L-T and E, maclovinus of 32.8 cm L-T, equivalent to 49 and 36.5% of their recorded maximum sizes respectively. As a result in 20-cm P. tessellata, the maximum fibre diameter was 300 mu m and 36% of fibres were in excess of 200 mu m The unusually large maximum fibre diameter, the general arrangement of the red muscle layer and the extreme pH lability of the mATPase of fast twitch fibres are all common characters of the sub-Antarctic and Antarctic Notothenioids, including Cottoperca gobio, the suggested sister group to the Notothenidae. (C) 2000 The Fisheries Society of the British Isles.

The status of Petalocotyle Ozaki, 1934 (Digenea : Gyliauchenidae), including the description of two new species from acanthurid fishes in Queensland, Australia

The status of Petalocotyle Ozaki, 1934 within the Gyliauchenidae Goto & Matsudaira, 1918 is reviewed. Two new species, P. adenometra from Prionurus microlepidotus (Amity Point, Queensland, Australia) and P. diverticulata from Acanthurus nigrofuscus and A. lineatus (Heron Island, Queensland, Australia), are described. The body plan of Petalocotyle conforms to that of members of the Gyliauchenidae (oral sucker absent, well-developed pharynx, complex oesophagus and characteristic male terminal genitalia), indicating justifiable inclusion in this family. A new diagnosis is given for the genus, such that Petalocotyle is now identified by the presence of an anterior, protuberant ventral sucker, long caeca, a large, sigmoid cirrus-sac containing a coiled ejaculatory duct, and an extensive vitellarium. We suggest that, of all the known genera of gyliauchenids, Petalocotyle may most closely resemble the 'archaetypal gyliauchenid', that is, it may be placed basally within the radiation of the Gyliauchenidae. However, derived characters, like diverticula in the reproductive system, indicate that some characters of individual members of Petalocotyle may be considered advanced and do not reflect an archaetypal condition. Parallels in the structure of the male and female genitalia of Robphildollfusium Paggi & Orecchia, 1963 and Petalocotyle, along with the shared morphology of the digestive tract, indicate possible phylogenetic links between the two genera. This affinity is difficult to infer using morphology alone and recommend that Robphildollfusium remain detached from the Gyliauchenidae.

Communication and camouflage with the same 'bright' colours in reef fishes

Reef fishes present the observer with the most diverse and stunning assemblage of animal colours anywhere on earth. The functions of some of these colours and their combinations are examined using new non-subjective spectrophotometer ic measurements of the colours of fishes and their habitat. Conclusions reached are as follows: (i) the spectra of colours in high spatial frequency patterns are often well designed to be very conspicuous to a colour vision system at close range but well camouflaged at a distance; (ii) blue and yellow the most frequently used colours in reef fishes, may be good for camouflage or communication depending on the background they are viewed against; and (iii) reef fishes use a combination of colour and behaviour to regulate their conspicuousness and crypsis.

Two new species of Neolebouria Gibson, 1976 (Digenea : Opecoelidae) from temperate marine fishes of Australia

Neolebouria moretonensis n. sp. is described from Gerres subfasciatus (Gerreidae) from Moreton Bay, south-east Queensland and N. lineatus n. sp. is described from Centroberyx lineatus (Berycidae) from off Rottnest Island, south-west Western Australia. C. lineatus represents a new host family and order (Beryciformes) for the genus. The two new species are distinguished within the genus by their entire, tandem to oblique testes and cirrus-sacs that do not extend into the hind-body, by being less than 1 mm in length, and by the position of the genital pore and the relative size of the forebody and post-testicular region. N. lineatus and N. moretonensis are very similar but are distinguished by their caeca which extend further posteriorly in N. moretonensis. There is no apparent pattern in the host-specificity of this genus.

Visual biology of Hawaiian coral reef fishes. II. Colors of Hawaiian coral reef fish

The colors of 51 species of Hawaiian reef fish have been measured using a spectrometer and therefore can be described in objective terms that are not influenced by the human visual experience. In common with other known reef fish populations, the colors of Hawaiian reef fish occupy spectral positions from 300-800nm; yellow or orange with blue, yellow with black, and black with white are the most frequently combined colors; and there is no link between possession of ultraviolet (UV) reflectance and UV visual sensitivity or the potential for UV visual sensitivity. In contrast to other reef systems, blue, yellow, and orange appear more frequently in Hawaiian reef fish. Based on spectral quality of reflections from fish skin, trends in fish colors can be seen that are indicative of both visually driven selective pressures and chemical or physical constraints on the design of colors. UV-reflecting colors can function as semiprivate communication signals. White or yellow with black form highly contrasting patterns that transmit well through clear water. Labroid fishes display uniquely complex colors but lack the ability to see the UV component that is common in their pigments. Step-shaped spectral curves are usually long-wavelength colors such as yellow or red, and colors with a peak-shaped spectral curves are green, blue, violet, and UV.

The Australian species of Lobatocreadium Madhavi, 1972, Hypocreadium Ozaki, 1936 and Dermadena Manter, 1945 (Digenea: Lepocreadiidae), parasites of marine tetraodontiform fishes

The genera Lobatocreadium, Pseudocreadium, Hypocreadium and Dermadena are redefined and host lists given. Provisional keys to species of Lobatocreadium, Hypocreadium and Dermadena are presented. The following species are described from (1) the Great Barrier Reef: Lobatocreadium exiguum from Balistapus undulatus and Sufflamen bursa; Hypocreadium cavum n. sp. from Abalistes stellatus (type-host) and Cantheschenia grandisquamis; H. grandisquamis n. sp. from Cantheschenia grandisquamis; Dermadena spatiosa n. sp, from Cantheschenia grandisquamis; and (2) southwestern Australia: D. stirlingi n. sp. from Meeschenia hippocrepis. The following new combinations are made: Lobatocreadium vitellosum (Ozaki, 1936) n. comb. (originally Leptocreadium); Hypocrendium balistes (Nagaty, 1942) n. comb. (originally Pseudocreadium); H. biminensis (Sogandares-Bernal, 1959) n. comb. (originally Pseudocreadium); H. indicum (Madhavi, 1972) n. comb. (originally Pseudocreadium); and H. galapagoensis (Manter, 1945) n. comb. (originally Pseudocreadium). Several nominal species of Pseudocreadium and Hypocreadium are considered incertae sedis.

Preptetos and Neopreptetos (Digenea: Lepocreadiidae) from Australian marine fishes

The genera Preptetos Pritchard, 1960 and Neopreptetos Machida, 1982 are redefined. The following species are described and/or recorded from marine fishes. From the Great Barrier Reef: Preptetos caballeroi Pritchard, 1960 in Naso annulatus, N. brevirostris and N. vlamingii; P. xesuri (Yamaguti, 1940) in Zebrasoma veliferum and Z.scopas; Preptetos cannoni Barker, Bray et Cribb, 1993 in Siganus doliatus and S. fuscescens; Preptetas luguncula sp. n. in Naso unicoris (type-host); P. impar sp. n. in Lutjanus erythropterus (type-host) and L. malabaricus; Neopreptetos arursettae Machida, 1982 in Pomacanthus semicirculatus; and N. kurochkini (Toman, 1989) in Chaetodontoplus meredithi. From southwestern Australia: Preptetos rotto sp. n. in Nelusetta ayraudi (type-host), Neosebastes pandus, Oplegnathus woodwardi and Pagrus auratus. The new combination Preptetos trulla (Linton, 1907) (originally Distormum then Lepocreadium) is made and the species Lepocreadium areolatum (Linton, 1900) is considered likely to belong in Preptetos.

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. I! 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.

The Asian fish tapeworm, Bothriocephalus acheilognathi, in Australian freshwater fishes

Bothriocephalus acheilognathi was collected from 13 of 38 carp (Cyprinus carpio), 2 of 4 mosquito fish (Gambusia holbrooki), and 2 of 12 western carp gudgeon (Hypseleotris klunzingeri) in waterways of the Australian Capital Territory and New South Wales. This is the first record of this parasite in Australia, and its presence in H. klunzingeri is a new host record. B. acheilognathi presumably arrived in Australia with its introduced fish hosts and has since crossed into native fishes, This cestode may infect other native fish species, a potential that is significant given the high pathogenicity associated with infection in other known hosts.

Tubular eyes of deep-sea fishes: A comparative study of retinal topography

The world's deep oceans are home to a number of teleosts with asymmetrical or tubular eyes. These immobile eyes possess large spherical lenses and subtend a large binocular visual field directed either dorsally or rostrally. Derived from a lateral non-tubular eye, the tubular eye is comprised of a thick main retina, subserving the rostrally or dorsally directed binocular visual field, and a thin accessory retina subserving, the lateral, monocular visual field. The main retina is thought to receive a focussed image, while the accessory retina is too close to the lens for a focussed image to be received. Several species also possess retinal diverticula, which are small evaginations of differentiated retina located in the rostrolateral wall of the eye and thought to increase the visual field. In order to investigate the spatial resolving power of these retinae (main, accessory and diverticulum), the distribution of cells within the ganglion cell layer was analysed from retinal wholemounts and sectioned material in ten species representing four genera. In all species, the main retina possesses a marked increase in cell density towards a specialised retinal region (area centralis), with a centro-peripheral gradient range between 7.1 and 60:1 and a peak density range of between 30 and 55 x 10(3) cells per mm(2). The accessory retinae and the transitional zone between the main and accessory retinae possess relatively low cell densities (between 1 and 10 x 10(3) cells per mm(2)) and lack an area centralis. Retinal diverticula examined in four species possess mean ganglion cell densities of between 7.2 and 109.4 x 10(3) cells per mm(2). Analyses of soma areas show that the ganglion cell layer of most species possesses cells with areas in a range of 8.0 to 15.4 mu m(2) in the main retina and between 15.1 and 17.4 mu m(2) in the accessory retina. The peak spatial resolving power of the main retina of the ten species varies from 4.1 to 9.1 cycles per degree. The positions of the retinal areae centrales relative to each species' binocular visual field are discussed in relation to what is known of feeding behaviour of these fishes in the deep-sea.