Some helminth parasites of marine fishes of south Africa: family Opecoelidae (Digenea)

The following digeneans are described, recorded or figured from South African waters: Pseudopecoelus ablennesi sp. nov. from Ablennes hians; Coitocaecum capensis sp. nov. from Clinus superciliosus, C. cottoides, Gynutoclinus rotundifrons, Xenopoclinus kochi and X. leprosus; Dactylostomun griffithsi sp. nov. from Cheilodactylus fasciatus; Margolisia vidalensis gen. nov., sp. nov. from Trachinocephalus myops; Pachycreadium obovatum from Sparodon durbanensis, Diplodus cervinus and Cheilodactylus fasciatus; Allopodocotyle recifensis sp. nov. from Pterogymnus laniar; Helicometra fasciata in Arius feliceps, Chirodactylus brachydactylus, Clinus capensis, C. cottoides, C. superciliosus, Gynutoclinus rotundifrons, Pachymetopon blochii, Pomadasys olivaceus, Pomatomus saltator, Xenopoclinus kochi and X. leprosus; Helicometrina nimia from Rhonciscus anus. The other taxa discussed are the genera Pseudopecoelus, Coitocaecum (synonyms Ozakia, Pseudocoitocaecum, Paradactylostomum), Dactylostomum, Pachycreadium and Allopodocotyle. In discussion the following new combinations are made: Coitocaecum (formerly Pseudocoitocaecum) bombayensis (Ahmad, 1983); C. (formerly P.) thrissoclesis (Bilqees, 1972); Dactylostomum (formerly Ozakia) iniistii (Yamaguti, 1970); D. (formerly O.) pfluegeri (Yamaguti, 1970); D. (formerly Coitocaecum) xesuri (Yamaguti, 1940); Allopodocotyle (formerly Podocotyle (Pedunculotrema) israelense (Fischthal, 1980); Allopodocotyle (formerly Podocotyle) jaffensis (Fischthal, 1980).     

A new species of Phyllodistomum (Digenea: Gorgoderidae) from Australian and New Zealand freshwater fishes with notes on the taxonomy of Phyllodistomum Braun, 1899

Phyllodistomum magnificum sp. nov., is described from the urinary bladder of Australian and New Zealand freshwater fish. Australian hosts were Anguilla reinhardtii, Tandanus tandanus, Hephaestus fuliginosus and Scortum hilli. New Zealand hosts were Anguilla australis and A. dieffenbachii. A presumed part of the life-cycle is described. Typical cystocercous cercariae are produced by sporocysts in the gills of a Pisidium species and are eaten by aquatic arthropods in which they encyst. The taxonomy of the genus Phyllodistomum is discussed and it is suggested that those species with cystocercous cercariae form a phylogenetic unit with Gorgodera, Gorgoderina, Progorgodera and Gorgotrema species.     

Ultrastructure of spermatozoa and spermatogenesis in Octopus minor (Sasaki, 1920) (Cephalopoda: Octopoda)

Octopus minor is widely distributed along the coastal areas of the west Pacific Ocean. This paper investigates spermatozoa, spermiogenesis from the testes, and spermatophores using light and electron microscopy. Mature spermatozoa are about 650 µm long. The head includes mainly the acrosome and nucleus. The acrosome consists of a striated cone surrounded by a single helix. The nucleus is cylindrical, homogeneous and of high electron density. The neck is short and connected with the head through the internal nuclear fossa. The axoneme connects the head, neck and tail. The tail is divided into middle, principal and final pieces. The ‘9 + 9 + 2’ structure is surrounded by a mitochondrial sheath, which includes 9–11 mitochondria in transverse section. The sperm morphology is compared with the ultrastructure of other cephalopod spermatozoa, and taxonomic and phylogenetic implications are discussed.     

Synopsis of the life cycles of Digenea (Platyhelminthes) from lagoons of the northern coast of the western Mediterranean

The present document reports on the large amount of data relating to digenean parasites recorded from or known to be present in various hosts in lagoons of the northern coast of the western Mediterranean, which has been compiled from the literature of more than a century. In these lagoons, at least 72 nominal species of digeneans have been recorded. This total corresponds to approximately 12% of the 584 “marine” digenean species reported for Europe. Data are provided on the life cycles of 56 digenean species. The life cycle has been totally elucidated for 44 species (25 from fish, 19 from birds), and partly for the other 12 species (seven from fish, five from birds). This means that the life cycle is known for 61.1% of the recorded fauna (44/72) and partly for 16.7%, but remains unknown for 22.2%, making it, in this respect, one of the best understood digenean marine faunas in the world. In addition, a checklist is provided dealing with the cercarial and metacercarial forms recorded from lagoons of the northern coast of the western Mediterranean, which have been described only on the basis of characters of these larval stages and which remain without demonstrated links to a corresponding sexual adult stage in a vertebrate.     

Cercaria hastata sp. nov. (Digenea: Trematoda) in Bullia digitalis,a sandy beach surfing whelk from the Western Cape coast of South Africa: epidemiology and sex linked phenomena

Morphometric and sex linked phenomena in male Bullia digitalis, from the Western Cape coast of South Africa, are related to infection with a digenean microphallid larva described here for the first time and named Cercaria hastata. Penis shedding in Bullia is not uncommon. Most of the stumps are found on infected whelks, and this is probably due to parasitic inhibition of an otherwise rapid regeneration. The infection also abolishes sperm production. Stumps were never seen on sperm producing males, all of which have large penes, and in non-infected males, shedding occurs only in non-producers. In large non-infected Bullia, those which have underdeveloped penes and are non-producers of sperm may be transient intersexes. This is supported by the exhibition of protandry indicators such as brooding, nonsize preferential mate selection and gregariousness. Infection prevalence is size dependent, large whelks being more commonly infected; but parasitic gigantism is thought unlikely as Bullia is iteroparous.     

Ultrastructure of the prezoeal cuticle and integument of the first zoea of Pagurus brachiomastus (Thallwitz) (Anomura,Paguridae) just after hatching

Transverse sections of the prezoea stage of Pagurus brachiomastus (Thallwitz) were made to determine the fine structure of the prezoeal cuticle and the exoskeleton of the first zoea, by using transmission electron microscopy. The thin cuticle covering the newly hatched prezoea is 15–17 nm thick, which is approximately 24 times thinner than the zoeal cuticle. High resolution revealed a trilaminar structure of the prezoeal cuticle, which is composed of an outer layer, approximately 4·4 nm thick, a mid lighter layer, approximately 3·5 nm thick, and an inner layer, approximately 7·7 nm thick. During the prezoeal stage, the inner zoeal exoskeleton consists of an epicuticle and an exocuticle, measuring approximately 0·36 μm thick. At this stage, there were no indications of the formation of endocuticle.     

Some helminth parasites of marine fishes of South Africa: Santeria rubalo gen. et sp. nov. (Digenea: Cryptogonimidae)

A new genus and species, Santeria rubalo, is described from the sparid fish Cheimerius nufar from the south-western Indian Ocean. It is placed in the cryptogonimid subfamily Neochasminae and is distinguished from Paracryptogonimus and Apophallus mainly by its oral spination, which consists of six to eight annular rows of spines.     

Tetrastichinae (Hymenoptera: Eulophidae) associated with spider egg sacs

Aranobroter rayorae, gen. et sp. n., is described as a gregarious predator of spider eggs within egg sacs of Metepeira incrassata (Araneidae) from Veracruz, Mexico. Baryscapus uetzi, sp. n., is described as an internal parasitoid of A. rayorae. The biology of these two species is discussed. A review of Tetrastichinae associated with spider egg sacs includes new North American records.     

The Cassidininae Hansen, 1905 (Crustacea: Isopoda: Sphaeromatidae) of Australia

The Cassidininae of Australia are revised. The status of the subfamily is assessed and it is concluded that, as presently constituted, the Cassidininae is an artificial taxon. It is maintained here as a taxon of convenience (sensu lato) until the other sphaeromatid subfamilies can be reassessed, but a new diagnosis (sensu stricto) is given. The genus Cassidina is redescribed. Three new genera are established: Agostodina gen. nov. (type species: A. munta sp. nov.), Apemosphaera gen. nov. (type species: A. naranagi sp. nov.) and Discidina gen. nov. (type species: D. banawarra sp. nov.). New diagnoses are provided for the genera Cassidina Milne Edwards, Chitonopsis Whitelegge, Cassidinidea Hansen, Paracassidina Baker, Syncassidina Baker and Platysphaera Holdich and Harrison. The genus Dies is placed in synonymy with Cassidinidea and an annotated list is given of all species of the genus. The following new species (excluding the new type species) are described: Chitonopsis booyoolie, Agostodina munta, Paracassidina anasilla, P. bakeri, P. bamarook, P. bilbie, P. cervina, P. dama, P. fuscina, P. incompta, P. kutyo, P. munna, P. petala, P. prolata, P. wurrook and Cassidinidea korpie. Keys to the Australian genera and species are given.     

On the occurrence of blood flukes (Sanguinicolidae: Trematoda) in British freshwater fish

Summary

A new genus, Cahara, is described, based upon Dalpada brevivitta Walker, as its type species C. brevivitta (Walker) comb. nov., C. confusa (Distant) comb. nov. and C. jugatoria (Lethierry) comb. nov. are redescribed and illustrated. C. murreeana sp. nov., C. montana sp. nov., C. kightleyi sp. nov., C. chaubattia sp. nov., C. bhowaliana sp. nov. and C. metallica sp. nov. are described as new. The genus Cahara occurs in the subhimalayan region of India, Pakistan and Nepal. Its members feed on deciduous trees, apple, walnut, fir, deodar, Bauhinia, etc. Superficially, the species resemble one another, as well as members of Dalpada s. lat. in their coloration and some have been confused with species like Dalpada versicolor in the past, but certain characters, like the shape of the head, the simple second antennal segment and more particularly the male and female genitalia, distinguish the genus Cahara from all others. A key to the species of Cahara is provided.     

New species and records of earthworms from Jamaica with notes on the genus Eutrigaster Cognetti, 1904 (Octochaetidae: Oligochaeta)

Details are presented of earthworm collections from Jamaica. Eleven species are reported, eight being new records of which two are new species, to bring the total number of species known from the island to 16 and the number of families represented to six. The geographical affinities of each species and its faunal status are summarized. The new species are members of the genus Eutrigaster Cognetti (Octochaetidae) whose validity is reviewed; a table is provided for the identification of the 11 Central American and Caribbean species currently included in the genus.     

Larval development of the fiddler shrimp,Metapenaeopsis stridulans (Alcock, 1905) (Decapoda: Penaeidae) reared in the laboratory

Larvae of Metapenaeopsis stridulans (Alcock, 1905) from Malaysia were successfully reared in the laboratory from the egg to the 1st post-larval stage. The larvae developed through six naupliar, three protozoeal and four mysis stages. The morphology of all these larval stages is described and figured.     

Immature stages of Chinavia musiva (Berg, 1878): a unique pattern in the morphology of Chinavia Orian, 1965 (Hemiptera,Pentatomidae)1

Specimens of Chinavia musiva were collected in Parque Estadual do Espinilho (Barra do Quaraí County, RS, Brazil). Insects were reared under controlled conditions (24±1°C; RH 70±10%; 12h L:12h D), and fed on green beans (Phaseolus vulgaris L.). Eggs of C. musiva differ from the pattern observed in other species of the genus due to chorion colour and surface, and aero‐micropylar processes, number and shape. Exclusive features of the species in the nymphal stage are head and thorax dull; variegated pattern of abdomen, and openings of the scent glands in conspicuous tubercles. Developmental time was, on average, 52 days; females laid more frequently egg masses with 14 or 42 eggs. Females collected from the field as nymphs exhibited higher reproductive performance than females reared on green beans as nymphs and adults, suggesting that wild hosts could be essential for the species life cycle.     

Provenance and status of Galaxias smithii Regan (1905) (Teleostei: Galaxiidae)

Galaxias smithii (Regan, 1905) (a junior synonym of G. platei Steindachner) is known only from the holotype, ostensibly collected from the Falkland Islands by Sir A. Smith. No further specimens of this fish have been reported from the islands, despite a recent intensive collection trip (146 sites in November, 1999). Analysis of material and documentation associated with the holotype and its purported collector, and additional information associated with other galaxiid specimens in the Natural History Museum, London, cast doubts on the authenticity of the origin and collector of the specimen. It is therefore suggested that occurrence of G. platei in Falkland Islands freshwaters should be rejected unless and until evidence to the contrary is obtained.     

Ultrastructural study of the proboscis of Malacobdella grossa (Nemertea: Hoplonemertea)

The proboscis of the symbiotic nemertean Malacobdella grossa was examined with transmission electron microscopy to reveal more features of bdellonemerteans for phylogenetic analysis. General morphology of the proboscis of Malacobdella corresponds to that of a typical hoplonemertean: the middle chamber is present; the nervous system of the proboscis is embedded in the connective tissue between the inner and outer longitudinal muscle layers; the radially arranged nerve trunks are clearly seen over a considerable portion of their extent. Unique features (i.e. autapomorphies) of Malacobdella’s proboscis include: interwoven longitudinal muscle fibres; nerve plexus in the anterior part of the proboscis; absence of mucus glands; presence of subepithelial glands; reduced musculature in the middle chamber; and absence of glandular epithelium in the posterior chamber.     

On the natural history of the South American pepper frog,Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae)

Some species of Leptodactylus of the L. pentadactylus group lay their eggs outside water but the tadpoles need to reach water to complete the larval phase; other species complete development in terrestrial nests. Here we present details of the reproduction of L. labyrinthicus in south‐eastern Brazil. The proportion of tadpoles and trophic eggs in aged egg clutches was determined, as well as the growth of the tadpoles while in the nest. The gut contents of tadpoles that were in egg clutches of frogs were analysed. Adult males did not differ from females in size and had hypertrophied forearms and an enlarged spine on the thumb. Reproduction was initiated with the first rains of August/September and extended to mid‐January. Calling and spawning occurred at permanent or temporary water bodies. The foam nests were built in excavated basins outside of, but close to the water. The male determined the place of the basin construction; after amplexus, the female completed the excavation. The amplexus was axillary. One female spent the day after spawning in the foam. The eggs were pale grey, the yolk averaging 2.3?mm in diameter. The mean number of eggs was 2101 per egg clutch. The number of tadpoles in individual nests varied between 0.05% and 11.40% in relation to the total laid eggs. The tadpoles entered water when rains flooded the basin. The tadpoles grew to 12 times the weight of an individual egg while in the nest; no nesting tadpole was beyond stage 25. The longest time we followed tadpoles in a nest was 25 days. Tadpoles were found preying upon eggs of three other frog species and upon conspecific eggs. Males fought by grasping each other in a belly‐to‐belly position; the powerful arms and the thumb spines represent weapons. Even though males can reach maturity in the season following birth, small size would prevent them from establishing their own territory. All the species of the L. pentadactylus group may build their foam nests within excavated basins. The basins may protect the eggs and embryos from cannibalistic tadpoles and may have an anti‐desiccation effect. In order to produce trophic eggs, the female may delay laying additional unfertilized eggs until after the male has abandoned the foam nest. Anuran eggs represent an important food item for tadpoles after they leave the nest.     

Cercaria bucephalopsis haimeana (Lacaze-Duthiers, 1854) (Digenea: Bucephalidae) in the cockle,Cardium edule L. in South Wales

Summary

Some variations in the percentage infection of the cockle, Cardium edule L., on Llanrhidian sands, South Wales with Cercaria bucephalopsis haimeana (Lacaze-Duthiers, 1854) are described.

Vertical variations in percentage infection are related to the population density of the final hosts and the seasonal variation with the breeding cycle of the first intermediate host. Only spent adult cockles, over 18·0 mm long and one year old, are infected, the highest percentage infection occurring in three-year old cockles. A decline in the percentage infection in older cockles suggests an increase in the mortality of infected specimens together with an increase in resistance to infection with age. Medium-sized cockles have a higher percentage infection than smaller and larger cockles of the same age. The parasite causes a decrease in the host's shell growth rate but an improvement in the flesh yield.

The possible reasons for the variations in percentage infection and the effect of the parasite on the host are discussed.     

Qualitative relations of egg size,egg production and colony size in some ponerine ants (Hymenoptera: Formicidae)

The sizes of eggs and reproductives of 13 species of ponerine ant were measured, and information about the mature colony sizes, ovarial anatomy and individual fecundities of a selection of ponerine species was assembled. Inter-specific variation in the size of colonies was found to be poorly related to aspects of individual fecundity, and although the few cases of polygyny were associated with larger colony sizes, monogynous species often attained even larger sizes. Within the subfamily individual fecundity may be increased primarily by a decrease in the maternal investment in individual eggs, and perhaps to a lesser extent by an increase in the number of ovarioles in each ovary or an increase in the length of each ovariole. The diet of a species and the longevity of adult worker ants relative to the duration of their larval development are suggested as factors besides reproductive characteristics that might also contribute to differences in colony size.     

Ultrastructure of the pereopodal dactyls in the family Phronimidae Dana, 1852 (Crustacea: Amphipoda: Hyperiidea)

Species of the Phronimidae were studied for the micromorphology of their pereopods. Novel structures were found on the dactyls and are described in detail. A hypothesis is advanced that these structures serve also for external digestion and absorption of the tissues of their gelatinous plankton hosts.