A description of Ucides occidentalis Ortmann, 1897 (Crustacea : Decapoda : Ocypodidae) zoea I.

ABSTRACT

In order to facilitate the ecological study of the economically important red mangrove crab Ucides occidentalis, we describe the zoea I phase using samples hatched from gravid females taken from the Guayas River Estuary of Ecuador. No other phases of this species’ larval development have been described. The morphological differences between this developmental phase in U. occidentalis and its single congener U. cordatus that may be diagnostic include the number of segments in the pleon, the setation pattern of the basial endopodite of the maxillule, and, in maxillipeds I and II, the segmentation of the terminal plumose natatory setae.     

The life-history of Anoplocnemis curvipes F. (Coreinea,Coreidae, Heteroptera) A pest of fresh cowpea pods

Summary

Facts are given on the preoviposition and oviposition of mated females of A. curvipes. The size, shape, colour, incubation and hatching of eggs are described. The morphology and development of neanides at various stages are described—and compared with some data on the egg and neanide periods of a related species A. phasiana. Differences are pointed out between the neanides and adults of A. curvipes and the longevity and sex ratio of the adults are discussed.     

Laboratory rearing of the larval stages of Carcinus maenas (L.) [Crustacea: Decapoda]

Summary

Larvae of Carcinus have been reared to the crab stage for the first time in the laboratory. Artemia nauplii were successful as food from Stage II zoeae onwards and Stage I zoeae fed and moulted successfully on the dinoflagellate Prorocentrum. Animal foods smaller than Artemia were not tried, but the larvae or eggs of molluscs, echinoderms or polychaetes would probably be suitable. Entirely algal diets were unsatisfactory for complete development.

On diets of Prorocentrum and Artemia, the overall survival rates to first crab stage were about 30% and the average total development time was 57·7 days. Average duration of each larval stage, in days, was 14·8 (zoea I), 7·9 (zoea II), 9·6 (zoea III), 10·0 (zoea IV) and 15·4 (megalopa).     

A new species of Prosimulium Roubaud (Diptera:Simuliidae) from Rhodesia

Summary

A new species of Prosimulium from Rhodesia is described and placed in the damarense-group; this species-group is defined and keys are given for the identification of its three constituent species in larval, pupal and adult stages.     

The Conidae (Mollusca: Gastropoda) of India

Summary

The polyp and immature medusa stages of Cladonema californicum Hyman, are described. The life cycle of the species was observed in the laboratory and took about 47 days to complete under laboratory conditions. Field collections from Bodega Harbor indicated that the medusae and reproductive polyp are present all year. A review of the taxonomy of the genus reveals that there are possibly only two valid species of Cladonema if one bases species separation on the medusa alone: C. radiatum and its ‘varieties’, and C. californicum. Additional work is needed to elucidate the relationships among the described varieties of the medusae of C. radiatum and the morphology of their respective polyps before further revision of the genus can be attempted.     

Field and laboratory observations on reproductive aspects of Pseudopaludicola ameghini (Cope, 1887) (Leptodactylidae: Leiuperinae)

ABSTRACT

The genus Pseudopaludicola includes small-sized anurans, widely distributed throughout South America. Twenty-three out of the 25 species occur in Brazil. Although described more than a century ago, from mid-southern Mato Grosso state, central Brazil, Pseudopaludicola ameghini is poorly known. Here we describe the characteristics of reproductive site, amplexus, egg-laying behaviour, eggs and tadpoles of P. ameghini based on specimens and observations performed in the vicinities of the type locality. Pairs of P. ameghini reproduce in shallow and slow groundwater established on hydromorphic terrains, in open environments amidst the Brazilian Cerrado savanna. Reproductive activity occurred between 17:00 and 21:00 h at two sites studied from December 2013 to April 2014. Amplexus is axillary. Eggs are spherical, with a mean diameter of 5.1 mm (yolk plus jelly envelope). Oviposition occurs in shallow sites at a depth of nearly 2.0 cm. Females deposit their eggs one at a time, directly onto sediment at the bottom of waterbodies or attached to submerged vegetation. The tadpole body is oval in dorsal view and globular/depressed in lateral view; eyes are large and dorsally positioned. Nares are large, round, with a small apophysis on marginal rim, dorsally positioned, near the eyes. The spiracle is short, with posterodorsal opening. The oral disc is anteroventral, emarginated laterally, with one dorsal and two ventral gaps; the tooth row formula is 2(2)/2(1), and the upper jaw sheath is ‘arc’ shaped. Pseudopaludicola ameghini has a unique behaviour of oviposition among members of the genus. The differences in reproductive pattern and larval characteristics of P. mystacalis and P. ameghini reinforce the taxonomic validity of the latter, questioned until recently.     

Host ranges of parasitoids (Hymenoptera: Braconidae and Ichneumonidae) reared from Epermenia chaerophyllella (Goeze) (Lepidoptera: Epermeniidae) in Britain,with description of a new species of Triclistus (Ichneumonidae)

The complex of parasitoids attacking larval stages of Epermenia chaerophyllella in Britain is outlined, and the host range of each of the species recorded (three braconids and four ichneumonids) is discussed. ‘Ecological’ factors, such as the behavioural similarity of unrelated hosts during the vulnerable parts of their life histories, seem to have been important in the evolution of the host associations of several of these parasitoids, even though they are koinobionts. A new species, Triclistus epermeniae Shaw and Aeschlimann, is described.     

Larvae of Homola (Crustacea; Dromiacea) from South Africa

Summary

Five zoeal stages of probably a single Homola species from the S.E. Atlantic are described. There are six zoeal stages in this species, of which the first is lacking from the present series. The zoeae probably belong to Homola barbata Fabr., linking the stages previously described by Pike and Williamson (1960) and by Rice (1964), giving a good idea of the complete larval development of this genus. Anomalies in the published work, however, point to the existence of taxonomic problems not previously apparent from studies on the adults alone.

The absence of exopods from the legs of these larvae adds further support to the contention that the grouping of the Dromiidae and Homolidae together in the Dromiacea is artificial.     

The larval and post-larval development of Gibbs's spider crab,Pisa armata (Latreille) [family Majidae: subfamily Pisinae], reared in the laboratory

Summary

The larvae and first crab stage of the spider crab Pisa armata are described from laboratory reared material. The larval stages are compared with previous accounts and with those of Pisa tetraodon. Larval affinities with other genera of Pisinae are discussed.     

Larval development of Pandalus gracilis Stimpson (Crustacea: Decapoda: Pandalidae) reared in the laboratory

The complete larval development of Pandalus gracilis Stimpson is described based on larvae reared in the laboratory. The species has four larval stages (stages 1–4) and one postlarval stage (stage 5). The survival rate of the postlarva stage is very high. Of the 40 larvae reared individually, 39 larvae moulted to the postlarva stage within approximately 21 days at a rearing temperature of 15°C. Larval morphological characteristics of the species are described and figured. Larval development of P. gracilis is compared with other Pandalus and Pandalopsis species. Komai (1999 Komai, T. 1999. A revision of the genus Pandalus (Crustacea: Decapoda: Caridea: Pandalidae).. Journal of Natural History, 33: 1256–1372.  [Google Scholar]) divided species of Pandalus into four species groups based on adult morphology. Pandalus gracilis belongs to the P. hypsinotus group. In this study, using larval characters, the P. hypsinotus group can be divided into two groups by the appearance of the mandibular palp and the shape of the telson: the first group contains P. hypsinotus and P. danae, and the second group contains P. gracilis, P. prensor, and P. nipponensis.     

Survival and reproduction of the mussel Xenostrobus securis (Lamarck) (Mollusca; Bivalvia; Mytilidae) in a Western Australian estuary. Pt. II: Reproduction,growth and longevity

Summary

Growth, longevity and breeding characteristics of populations of the mussel Xenostrobus securis in the Swan Estuary are remarkably variable, both between one year and another and between upstream and downstream localities. These characteristics and their variability may be accounted for by the species' physiological responses and limitations to variable salinity conditions. The Swan Estuary is subject to extreme temporal and spatial variations in salinity. Temperature has only a secondary significance on the biology of the mussel in this estuary.

Activity including growth is inhibited at chlorinities below 2‰. This occurs each winter during the discharge period. At Crawley (downstream) the discharge period rarely lasts more than a few weeks in mid winter, but at upstream limits of the estuary (e.g. Barker Bridge) it is highly variable and may last as long as seven months. Consequently the period of no-growth which corresponds to the discharge period varies between downstream and upstream populations and the total annual growth increment varies accordingly. Similarly the duration of the no-growth period and the total annual growth increment varies from year to year at upstream localities.

At Crawley mussels live only one year. At that locality there is almost total mortality of adults soon after spawning. The relationship of the post-reproductive mortality to intensity of reproductive effort is discussed. At Barker Bridge heavy post-reproductive mortality was not observed and animals may live two years or more. This greater longevity at Barker Bridge is considered to have survival advantage for the population which is living in an unstable and inconsistent environment. Downstream conditions are more seasonally regular and the populations there can rely on having optimal conditions each year.

Spawning begins at the downstream end of the estuary in November or December when the chlorinity rises to the critical lower limit for larval development (8 to 9‰. Cl). A wave of spawning moves up the estuary as the summer progresses, following the zone of optimal salinity conditions. It does not reach Barker Bridge until February or March. In 1964 the chlorinity did not reach the lower limit for larval development at Barker Bridge and no spawning or spatfall occurred there.

It is considered that X. securis is physiologically well adapted for persistence in an estuarine environment characterized by variable and unstable salinity conditions.     

The aedeagus,its musculature,and ‘retournement’ in Aspidomorpha miliaris F. (Coleoptera,Phytophaga, Chrysomelidae)

Summary

The aedeagus and its musculature in Aspidomorpha miliaris have been described in detail. They have been found to be closely comparable to those in the Chrysomelid Galerucella birmanica, which has been studied earlier from this standpoint by one of the present authors. In A. miliaris, however, the spiculum has shortened, and consequently the protractors of the aedeagus have been brought close to the proximal retractors of the aedeagus to form a basal muscular bulb for the aedeagus. The muscular bulb seems to help in maintaining the fluid pressure necessary for eversion of the internal sac of the aedeagus during copulation over a long period without strain on the general abdominal musculature. Shortening of the spiculum on the other hand has taken away the function of retraction from the proximal retractors of the aedeagus. The aedeagus is retracted after copulation by repeatedly stroking the protruding aedeagus with the hind legs and by pressing it against the substratum. The aedeagus undergoes ‘retournement’ through 180° after the adult has ecloded from the pupal skin. The ‘retournement’ is due to degeneration of the left member of the pair of protractors of the spiculum, while the right member exerts a unilateral pull on the dorsal surface of the genital tube, bringing about turning of the genital tube, and then survives as an apparently median muscle. In a small percentage of cases the left protractor survives to become the functional and the apparently median protractor of the spiculum, while the right member of the pair degenerates, and the consequent ‘retournement’ of the aedeagus is anti-clockwise.     

Studies on Alenophalera bronneomixia (Lepidoptera: Notodontidae)—a pest of the West African indigo plant,Lonchocarpus cyanescens (Papilionaceae)

Summary

This paper is concerned with the general biology of the notodontid moth, A. bronneomixia whose larvae are found to be serious defoliators of the West African indigo plant, Lonchocarpus cyanescens.

At temperatures fluctuating between 21°C and 29°C (mean 22·5°C) and humidities between 70 to 95 per cent eggs developed and hatched in a mean of 11·1 days from deposition, mean hatch being 93 per cent.

Under the said environmental conditions, the life cycle from egg to adult entailed six larval instars and a prepupal stage before the real pupa, all lasting 60 to 80 days. Larvae were strongly monophagous, fed communally and in nature pupated in soil/litter very close to the foot of their invaded food plant.

Adults were retiring and in the field deposited clusters of numerous eggs preferably on the abaxial surfaces of their food plants. In nature, this moth's population seemed strongly regulated by high egg and larval parasitization, larval predation and fungal attacks at the pupal stage.     

Nouveaux Lamiaires du British Museum (Natural History), (Coleoptera,Cerambycidae)

Summary

Detailed examination of the cheliceral flagella of four British species (C. cimicoides, L. nodosus, A. dubius, and P. scorpioides) belonging to the family Chernetidae shows that the number of blades is stabilized by the protonymph. The morphology and pattern of growth of the blades are described, and the significance of the flagellum as a useful taxonomic character at the generic, if not specific level, is discussed.     

Gyroptychius (Rhipidistia,Osteolepidae) from the Middle Devonian of Scotland

Summary

The ethmoid endocranial structures of Gyroptychius sp. are described using unique material from the Middle Devonian nodule bed at Dipple, Morrayshire. This rare opportunity for comparison of different osteolepid rhipidistians confirms the general pattern of structure suggested in previous studies.     

Growth ‘rules’ and the larvae of decapod crustaceans

Summary

Statements that have attempted to express the relationship between the sizes of successive arthropodan instars are examined with reference to published data on larval decapod crustaceans.

The conclusions reached are (a) that ‘Brooks's Law’, which simply states that the lengths of successive instars form an exponential series, generally holds good in decapod larvae, (b) that ‘Przibram's Rule’, stating that the weight increase between instars is always by some power of 2, is not supported by the observed length changes, and (c) that Gurney's suggestion that growth factors in decapod larvae do not normally exceed about 1·5 is not applicable to the order as a whole, but may be valid for some sub-groups within it.     

The carboniferous fossil lycopod Ulodendron landsburgii (Kidston) comb. nov.

Summary

A data gathering system controlled by microcomputer, recording swimming activity, is described. Prior to the breeding season, in a normal day and night regime, the delta prawn Palaemon longirostris shows a circadian swimming rhythm with peak activity at night. As the ovaries ripen and the prawns mate there is evidence of an additional tidal swimming rhythm. Females carrying eggs revert to nocturnal circadian swimming only. In ovigerous females the circadian swimming rhythm persists in continuous darkness with a free-running period of between 22 and 23 hours. The closely related and sympatric species Palaemonetes varians has similar patterns of swimming behaviour. It is suggested that the absence of newly hatched palaemonid larvae in the estuary is a result of the interaction of these adult swimming patterns with tidal flow and nocturnal hatching.     

A revision of the genus Heliconema Travassos, 1919, Physalopteridae (Nematoda)

Summary

It is accepted that the genus Ortleppina Schulz, 1927, is a synonym of the genus Heliconema Travassos, 1919.

Five valid species of Heliconema are recognized: H. heliconema, H. ahiri, H. baylisi, H. brevispiculum and H. longissima.

A new species, H. baylisi is described, and H. heliconema, H. brevispiculum and H. longissima are redescribed.     

Additional new species of Grouvellinus Champion 1923 (Insecta,Coleoptera, Elmidae) discovered by citizen scientists and DNA barcoded in the field applying a novel MinION-based workflow

ABSTRACT

Four new species, Grouvellinus nigerquadratus sp. nov., G. cruxniger sp. nov., G. luciaensis sp. nov., and G. borneensis sp. nov., are described from Borneo and illustrated in detail. Two additional species of the genus which remain undescribed are briefly diagnosed. The material was collected during Taxon Expeditions’ field course which involved citizen scientists, students and taxonomists. Specimens were collected at altitudes between 270 m and 750 m above sea level using fine-meshed hand-nets and blacklight traps. The morphological species delimitation based on morphology was supplemented and congruent with mtDNA sequences which are the first DNA barcodes for the genus from Borneo. They were obtained in the field using a newly developed rapid and accurate MinION-based workflow. The inter – and intraspecific genetic distances and the problems regarding cryptic species delimitation are discussed.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:4B1D0F3D-B303-46A5-86B4-C23454192327