A new stylochid flatworm (Platyhelminthes,Polycladida) from Victoria,Australia and observations on its biology

There are only four polyclad flatworms currently known from temperate waters of Victoria, Australia, although these turbellarians are common inhabitants of rocky shores. A new stylochid flatworm, Stylochus pygmaeus sp. nov. (Platyhelminthes, Polycladida) or oyster leech is described here from Port Philip Bay, Victoria. This flatworm was observed feeding on three species of barnacles by extending its pharynx over its prey and extruding copious amounts of mucus. Worms also preferred to prey on larger‐sized barnacles regardless of the species. Further observations indicated that these worms deposited eggs at night inside empty barnacle shells. Each eggmass was brooded for several days with the worms only moving off to feed. Each egg capsule contained multiple embryos and after 5 or 6 days, positively photo‐tactic, four‐lobed Götte's larvae emerged. Larvae metamorphosed to juvenile flatworms 1–2 weeks post‐hatching but failed to settle and survive.     

The distribution and habitat preferences of the Afro-European species of Dynamene (Crustacea: Isopoda)

Summary

The geographical distribution of the genus Dynamene is described in the light of the recent discovery of three new species. D. bidentata appears to have a Boreal distribution whilst that of D. edwardsi and D. magnitorata is Atlanto-Mediterranean. D. torelliae, D. bifida, and D. tubicauda have a Mediterranean distribution but the first species may extend into the Black Sea. Only one species, D. ramuscula, has been recorded outside the Afro-European region, in S.E. Australia. The ranges and habitat preferences of those species outside the Mediterranean overlap as do some of those within the Mediterranean, particularly in the Naples Bay region. Juveniles of D. bidentata inhabit and feed on intertidal algae while adults shelter in crevices and empty tests of Balanus perforatus, mainly below MTL. Settlement of males into barnacle tests appears to be random, but females show some degree of aggregation, perhaps to other females. Other species show the same change of habitat at sexual maturity and all inhabit intertidal or inshore localities.     

A revision of Bovichtus Cuvier, 1831 (Pisces: Bovichthyidae) from Australasia,with description of a new deepwater species from the New Zealand Subantarctic

The genus Bovichtus includes four species from the Australasian region, viz. B. variegatus Richardson, B. psychrolutes Günther, B. angustifrons Regan, and B. oculus n. sp. B. decipiens Regan and Aurion effulgens Waite are junior synonyms of B. variegatus and B. psychrolutes respectively. B. oculus, described from a specimen taken in 847–902 m on the Campbell Plateau in the New Zealand Subantarctic, is the first known deep water Bovichtus species. It differs from all congeners in having a very large eye (horizontal diameter <9·0 times in SL) and, alone with B. psychrolutes, has a patch of ctenoid scales on the body behind the pectoral fin base.     

Taxonomic and biological observations on the tiger flatworm,Maritigrella crozieri (Hyman, 1939), new combination (Platyhelminthes,Polycladida, Euryleptidae) from Florida waters

The tiger flatworm, Maritigrella crozieri (Hyman, 1939) (Platyhelminthes, Polycladida, Cotylea) new combination, is redescribed from eastern Florida and the Florida Keys. This marine flatworm is one of the most common polyclads within warm temperate to tropical west Atlantic, yet it has been misidentified consistently as a pseudocerotid. Animals were kept alive in the laboratory for 3 weeks for biological observations. Findings indicated that these euryleptids employ hypodermic insemination, with multiple copulations occurring over several days. Sperm was transferred in sperm bundles bilaterally with little apparent damage to the epidermis of the copulating worms. Copulation sessions were variable and lasted an average of 15.4 min. In situ and laboratory observations indicated that M. crozieri fed exclusively on the mangrove ascidian Ecteinascidia turbinata Herdman, 1880, an individual consuming one prey zooid in an average of 17 min and an average of 19 zooids over 24h.     

The catfish genus Akysis Bleeker (Teleostei: Akysidae) in Indochina,with descriptions of six new species

Catfishes of the genus Akysis Bleeker occurring in the Mekong basin south of the Chinese border, in the Mae Nam Chao Phraya basin, in the Malay Peninsula and the basins in between are reviewed. Nine species are recognised, six of which are new: A. alfredi, A. ephippifer, A. recavus, A. similis, A. subtilis and A. varius. Two groups of species were identified: one group (the pseudobagarius group) is characterised by its members possessing a relatively elongate body, conspicuously subterminal mouths with the upper jaw strongly overhanging the lower, relatively large posterior and anterior nostrils closely located to each other and separated only by the base of the nasal barbel, and strongly-forked caudal fins. The second group (the variegatus group) is characterised by its members possessing a relatively deep body, the margins of the upper and lower jaws uniform, relatively small posterior and anterior nostrils located further apart with a distance between the base of the nasal barbel and anterior nostril, and emarginate or truncate caudal fins. The pseudobagarius group contains the following species: A. alfredi, A. Baramensis, A. fuscus, A. leucorhynchus, A. macronema, A. pseudobagarius, A. sinensis, A. similis, and A. subtilis. All other species of Akysis belong to the variegatus group. A key to the Indochinese Akysis is provided.     

The distribution of New Zealand and Australian terrestrial flatworms (Platyhelminthes: Turbellaria: Tricladida: Terricola) in the British Isles—the Scottish survey and MEGALAB WORMS

The New Zealand flatworm, Artioposthia triangulata, and the Australian flatworm, Caenoplana alba, have become quite widespread in the British Isles since their introduction, probably in the early 1960s. They are considered as pest species since they eat earthworms and consequently may affect soil structure and fertility. The distribution of the two species has been recorded by two surveys: a Scottish survey between 1991 and 1993, and a national survey, MEGALAB WORMS, in March 1995. The latter was organized as part of National Science Week by BBC TV Tomorrow's World, The Daily Telegraph newspaper and the Office of Public Service and Science. Results of both surveys are presented as distribution maps of confirmed records. New Zealand flatworms are common and widespread in Northern Ireland and Central Scotland, and occur less commonly in other parts of Scotland, and in Northern England. There are a few scattered records from Southern England. The Scottish survey has resulted in retrospective distribution maps. Australian flatworms are widespread in South West England, and are found in several places in North West England. There are also records from South and North Wales, Northern Ireland and one from Southern Scotland. There were many false and negative reports. There are records of both species from the Republic of Ireland.     

Meristic studies of the Gulf of California species of Merluccius,with a description of a new species

Two distinct species of hake are found in the Gulf of California, and in view of the commercial importance of at least one of these, a detailed taxonomical study was carried out. A new species of hake is described from the northern Gulf of California: Merluccius hernandezi. A new population of Merluccius angustimanus was located off the coast of the state of Sinaloa, Mexico. A provisional examination of specimens from this population shows that it differs in important characteristics from the specimens described by Garman (1899) from Panama.

Merluccius hernandezi and M. angustimanus from Sinoloa are immediately separable by the shape of their caudal fin and the lengths of their pectoral fins: in M. hernandezi the caudal fin has a central lobe and in larger specimens it is truncate, while in M. angustimanus it is emarginate; the pectoral fin projects well beyond the anus in M. hernandezi but not in M. angustimanus.

A meristic index was devised which can be used successfully to distinguish between the two species in the field: only 4·13% of specimens studied would have been wrongly identified using this index.     

Diversity of Salticidae (Arachnida: Araneae) in the historical and natural reserve ‘Martín García Island’, Argentina

From Martín García Island were collected 975 jumping spiders, from five environments, using beating net and manual sampling methods. Saitis variegatus Mello-Leitão, 1941 was the most abundant (24.62%). The sandy xerophilous forest had the highest species richness (23 morphospecies) and jungle showed the greatest spider abundance (n: 384). The sandy area was the least diverse and the last in relative abundance. Salticids represented 16% of the species recorded from Argentina, and the second largest family registered. The spider fauna found could be similar to that of the Southern Brasilian region, as occurs with scorpions. Two genera and two species are new records for Argentina. In addition, three new species of jumping spiders, as well as the discovery of the unknown male and female of two species, were registered. There was no record of cosmopolitan spiders or those with a large distribution range on the Island.     

Microhabitat diversity of Svalbard Bryozoa

Bryozoans are one of the major macrofaunal groups of the high polar regions. Here we present data on the nature of bryozoan assemblages in the Svalbard Archipelago sampled over 6 years between 1997 and 2002. Samples were collected with use of Van Veen grab, dredge and Scuba diving at depths ranging from 0 to 268?m. Among examined material (5026 items) bryozoans were present on one type of abiotic (stones) and 40 types of biotic substrata. The biotic substrata we investigated included algae (12 taxa) and invertebrates (28 taxa: Hydrozoa, Gastropoda, Bivalvia, Polychaeta, Crustacea, Ascidiacea, other Bryozoa). Both a priori ANOSIM (Global R?=?0.512, P?=?0.001) and cluster analyses reveal differences between the assemblages on different types of substrata. Cluster analyses distinguish two distinct groups of substrata. The first (stable) included stones, molluscs and Balanus balanus whilst the second (flexible) consisted of algae, hydrozoans and bryozoans. Bryozoan assemblages which colonized different substrata, varied in terms of species composition and their dominance. Bryozoan species were categorized as generalists, low‐specificity epibiotic species or locally abundant background species. No species were found to be substratum‐specific to any type. Among substrata with the richest bryozoan fauna were stones (156 taxa), Chlamys islandica (68) and Balanus balanus (62). There were clear patterns in the distribution of substrata colonized by bryozoans within the fjord system: those shallow near the mouth were rich whilst those in deeper water were depauperate. We consider environmental gradients such as siltation and processes related to depth to be responsible for such patterns.     

A new lycaenid butterfly exclusively associated with the subalpine sclerophyllous oak forests in Taiwan (Lepidoptera,Lycaenidae, Theclinae)

Subalpine sclerophyllous oak forest grows at high elevation in Taiwan, distantly separated from similar forest communities found in western China, Tibet and India. An investigation on bud‐breaking phenology of oaks and associated phytophagous insects in this community revealed an undescribed species of Teratozephyrus lycaenid. This and other oak‐associated insects suggest that the presence of this oak community in Taiwan resulted from a more widely distributed community. The newly discovered Teratozephyrus turned out to be most closely related to T. nuwaii, described from western China, and is described below as T. elatus sp. nov. Two other species of Teratozephyrus also inhabit Taiwan, but both are associated with broad‐leaved oak forests. Of them, T. arisanus is widespread both in China and Taiwan, is morphologically distinct from the other Teratozephyrus species and is exclusively associated with broad‐leaved oaks. The other, T. yugaii, probably gained its broad‐leaved oak association secondarily as no similar species is found in the broad‐leaved oak communities on continental Asia, and it favours cool, higher‐elevation environments even though its host plant ranges into far lower elevations.     

Prey capture and feeding behaviour in an endemic land flatworm from São Tomé Island

ABSTRACT

Two specimens of the endemic land flatworm species Othelosoma impensum Sluys & Neumann, 2017 from the volcanic island São Tomé were observed in the wild in Obo-National Park while they were preying on ants that had descended on a tree trunk after their nuptial flight. A maximum of 41 ants were assembled in a cluster by one of the flatworms, the insects being immobilised by mucus secreted by the worms. A strong cephalic retractor muscle facilitated capture of the mobile prey. Presence or absence of similar cephalic adaptations in other species of Othelosoma and other genera of land flatworms is discussed, as well as the effectiveness of the sticky mucus secreted by the worms during prey capture.     

Is the valid species Synchaeta monopus Plate, 1889 (Rotifera: Monogononta) a product of preparation artefacts?

The morphology of soft-bodied rotifers, including those of Synchaeta spp, can be strongly affected by preparation artefacts including contraction and deformation. The long-standing, valid species Synchaeta monopus is known exclusively from ethanol- or formaldehyde-preserved material and no live specimens of it have ever been described. Although this alone is cause for concern, we could also reproduce unique characteristics diagnostic for this species (e.g. the swollen body and the rudimental foot) by subjecting specimens of Synchaeta pectinata to the preservation conditions under which it was first described. This proxy experiment and comparisons to other Synchaeta species indicate that literature occurrences of S. monopus likely represent preserved and deformed specimens of Synchaeta cecilia or other marine species of Synchaeta, thereby highlighting the importance of thorough morphological investigations of the habitus using live specimens and of features that are unaffected by preservation (e.g. the trophi). We therefore recommend that S. monopus be listed as a species inquirenda until topotypes are examined. Furthermore, in ecological studies including rotifers, where the examination of preserved material is often unavoidable, we stress that light-microscopical images of the habitus and trophi of the specimens minimally be included to facilitate independent verification of the species assignments.     

News from a small island – first record of a freshwater shrimp (Decapoda,Atyidae, Caridina) from Peleng,Banggai Islands,Indonesia

The Indonesian island Sulawesi is well known for its fascinating fauna. Among the atyid and palaemonid freshwater shrimps described from Sulawesi are also a number of endemic species. In contrast, freshwater shrimps have never been reported from the nearby and smaller Peleng Island. Here we describe Caridina thomasi sp. nov. as a first record of an atyid freshwater shrimp from Peleng and compare it with atyids from Sulawesi and other localities. The new species is probably endemic to the island and shows some characters never described in the genus Caridina before. However, a molecular phylogeny of atyid shrimps from the Indo‐West Pacific based on mitochondrial DNA (16S) places C. thomasi within a clade of typical species of Caridina. We tentatively assign the new species to the genus Caridina and discuss the possibility of future changes in the classification of species in this genus.     

Redescription of Sclerhelia hirtella from Saint Helena,South Atlantic,and remarks on Indo-Pacific species erroneously referred to the same genus (Scleractinia)

Summary

Sclerhelia hirtella (Pallas, 1766), type species of Sclerhelia, is redescribed from samples from Saint Helena, South Atlantic, and referred to the family Caryophylliidae. Up to now there is no confirmation on the occurence of S. hirtella at any locality other than Saint Helena. Here, the species lives in rather shallow water but it is unknown whether symbiotic zooxanthellae are present in the soft parts.

The species from the Maldives and Indonesia known as Sclerhelia formosa (Alcock, 1898) is not congeneric with Sclerhelia hirtella but close to Madrepora oculata Linné, a species conventionally placed in the family Oculinidae.

The species from the Marshall Islands, described by Wells (1954) as Sclerhelia alcocki is a dendrophylliid coral identical with Dendrophyllia palita Squires & Keyes, 1967, from New Zealand. The Maldives are the third area where this species is known (the original record having been confused with another dendrophylliid species).     

Taxonomic revision and systematic notes on some Halecium species (Cnidaria,Hydrozoa)

Although the genus Halecium is easy to recognize, identifications at the species level are often difficult, this even for quite common and supposedly well‐known species of the north‐eastern Atlantic. This paper revises and re‐describes some Halecium species which resemble each other closely and which are not easy to distinguish. Additional information on a few rare species is also provided. The study is based on material collected from the North Atlantic, Mediterranean, South Africa, and New Zealand. Halecium scutum Clark, is recognized as a valid species and distinct from both H. beanii and H. halecinum; colony form and microscopic characters allow a distinction. The pinnate colony form of H. halecinum is a characteristic trait, but not all colonies show this growth form. Halecium beanii can occur in monosiphonic and polysiphonic colonies. Monosiphonic colonies of H. beanii have probably been misidentified by some authors as H. lankesterii. The differences of H. lankesteri to H. beanii and H. petrosum are discussed. The South African population of the reportedly cosmopolitan H. beanii has distinct gonothecae and could belong to a separate species. The Mediterranean Halecium mediterraneum is hardly distinguishable from the New Zealandic H. delicatulum, but it is kept separate mainly for biogeographic reasons. The rare Mediterranean Halecium banyulense is re‐described based on a second find from Naples. The male gonothecae of Halecium corrugatissimum are described for the first time.     

Morphological variation of Eucyclops elegans (Herrick, 1884) (Copepoda: Cyclopoida) in the Americas and comments on records of Eucyclops conrowae Reid, 1992

Based on an examination of material from different areas of the American continent, we evaluate the morphological variations of Eucyclops elegans (Herrick, 1884) with an emphasis on characters used in the current taxonomy of the genus. Eucyclops elegans is clearly a member of the serrulatus group. Differences in both female and male specimens from North America and South America and the lack of records in southern Mexico and Central America suggest that it is possible that this nominal species contains at least two taxa. Characters such as the ornamentation of the antennal basis and coxa of P4 are described for the tropical species E. conrowae Reid, 1992. This species is clearly not a member of the serrulatus group and differences with respect to the type specimens indicate that records of E. conrowae in Mexico do not correspond to this taxon and should be reassigned to other species.     

A remarkable new cave-dwelling Stylocellus (Opiliones,Cyphophthalmi) from peninsular Malaysia,with a discussion on taxonomic characters in the family Stylocellidae

A new opilionid species, Stylocellus globosus, is described from limestone caves near Ipoh (peninsular Malaysia). This is the third cave-dwelling species known in the genus Stylocellus; it shows various degrees of eye reduction and, due to the presence of anal glands in males, occupies a systematic position between the genera Stylocellus Westwood and Fangensis Rambla. Other characters, such as the presence of a smooth anal crest and details of gonopore complex of the penis, suggest relationship to Stylocellus sumatranus Westwood from Sumatra and to S. gryllospecus Shear from Borneo, respectively.     

Some European Processidae (Crustacea,Decapoda, Caridea)

Summary

The name Processa canaliculata Leach has been applied to a species other than that to which the holotype belongs. The species P. canaliculata Nouvel & Holthuis non Leach has no valid name; it is re-named P. nouveli, with type material from Monaco.

P. nouveli and P. canaliculata have been considered to be conspecific by one recent author. New characters for their separation are described from Irish Sea material.

The northern form of P. nouveli differs from the Mediterranean form sufficiently to be placed in a separate subspecies. The name P. nouveli holthuisi is proposed for it, with type material from the Irish Sea.

The distribution of the four species and subspecies of Processa known to occur in northern Europe is reviewed.