Profilicollis novaezelandensis n. sp. (Polymorphidae) and two other acanthocephalan parasites from shore birds (Haematopodidae and Scolopacidae) in New Zealand,with records of two species in intertidal crabs (Decapoda: Grapsidae and Ocypodidae)

Profilicollis novaezelandensis n. sp. (Acanthocephala: Polymorphidae) is described from the South Island pied oystercatcher Haematopus ostralegus finschi Martens (Haematopodidae) and the intertidal crab Hemigrapsus crenulatus (Milne Edwards) (Brachyura: Grapsidae) from the South Island of New Zealand. The new species can be distinguished from all the other species of the genus by a combination of the following characters: long neck (13% of total body length for adults) and a subspherical proboscis with 14–16 longitudinal rows of 7–8 hooks. The mud crabs Helice crassa Dana (Grapsidae) and Macrophthalmus hirtipes (Heller) (Ocypodidae) were also harbouring cystacanths and the bar-tailed godwit Limosa lapponica (Linnaeus) (Scolopacidae) juveniles of P. novaezelandensis. This is the first record of brachyuran decapods as intermediate hosts of Acanthocephala from New Zealand. P. antarcticus is recorded from three crab species (Helice crassa, Hemigraspus crenulatus and Macrophthalmus hirtipes) and two bird species (Haematopus o. finschi and Limosa lapponica) in New Zealand. An unidentified species of Plagiorhynchus was also found in two bird species (H. o. finschi and H. unicolor Forster). P. antarcticus and P. novaezelandensis are the first records of Profilicollis from New Zealand.     

Substratum preference of the tropical estuarine crabs,Uca tangeri Eydoux (Ocypodidae) and Ocypode cursor Linne (Ocypodidae)

The vertical and horizontal distribution of two burrowing mud crabs, (Ocypodidae) and Ocypode cursor Linne 1758 (Ocypodidae) are described for the Bonny Estuary (7° 00' E: 4° 20′ N), S. Nigeria. Substratum preference is the most prominent factor influencing distribution, but lack of tolerance to low salinities (< 6%_o) is also important, and prevents Ocypode cursor from occurring close to freshwater. The two species have slightly different sediment organic content and grade size requirements. Ocypode cursor was concentrated in well drained sandy sediment above mid-tide-level, whilst Uca tangeri was found in water-logged areas slightly above and below Mid-tide-level. This vertical demarcation is attributed to differential feeding and burrowing adaptations related to different substrata, rather than to differential tolerances to desiccation.     

The effects of burrowing of Helice tridens (De Haan) on the soil of a salt-marsh habitat

The physical and chemical effects of the burrowing activity of the mud crab Helice tridens (De Haan) on the soil of a salt-marsh habitat were investigated. Soil-turnover rate caused by burrowing activity was found to be ≈ 3% of the soil from the surface to a depth of 40 cm every day during the summer. The vertical distributions of leaf and stem fragments of the salt-marsh plant Phragmites australis (Trin.) and the vertical distribution of ammonium N concentration in the soil were also investigated. At locations in the marsh where there were many large burrows, numerous leaf and stem fragments were recognized in the soil, while in areas in the marsh containing only a few small burrows these fragments were scanty. The soil depths at which leaf and stem fragments were abundant, corresponded to the depths of the burrows. These results show that mud crabs bury fallen plant fragments in the soil by their burrowing activity. Ammonium N in the soil was also abundant at locations in the marsh where there were many burrows, indicating that organic matter, such as fallen leaves and stems, may be decomposed to inorganic nutrients which are useful to the salt-marsh plants.     

Responses of embryonic stages of the estuarine mud crab,Macrophthalmus hirtipes (Jacquinot), to salinity

Females of the estuarine mud crab, Macrophthalmus hirtipes (Jacquinot, 1853) (Ocypodidae) carrying newly-deposited eggs were maintained in salinities of 11‰, 18‰, and 36‰ at 10°C. In 11‰ salinity eggs swelled more than in the other salinities; embryonic development was retarded; and eggs did not hatch. In 18‰ and 36‰, rates of development were generally similar and successful hatching occurred after approximately 75 days. However, late-stage eggs in 18‰ were significantly (P<0.001) larger than those in 36‰, even though initial egg volumes were the same. Zoeae were morphologically similar, except that the dorsal spine was significantly (P<0.001) longer in 36‰ compared with 18‰.     

Buffering role of the intertidal anemone Anthopleura aureoradiata in cercarial transmission from snails to crabs

In nature, parasite transmission from one host to the next takes place within complex biotic communities where non-host organisms can reduce transmission rates, for instance by preying on infective stages. We experimentally investigated the impact of four very different non-host organisms on the transmission of the microphallid trematode Maritrema novaezealandensis from its snail first intermediate host to its crustacean second intermediate host. We show that in laboratory mesocosms, accumulation of parasites in juvenile stalk-eyed mud crabs, Macrophthalmus hirtipes (Ocypodidae), was not reduced in the presence of cockles, Austrovenus stutchburyi, barnacles, Balanus sp., or the algae Enteromorpha spp., three organisms whose feeding mode or general abundance could negatively impact the parasite's infective stages (cercariae). In contrast, the presence of the anemone Anthopleura aureoradiata in the mesocosms caused a more than 4-fold reduction in the number of parasites acquired by crabs when compared to control mesocosms. Observations on fluorescent-dyed cercariae confirmed that they are ingested by anemones. Given the often high densities of anemones on mudflats, they may represent an important regulator of the abundance of M. novaezealandensis, and thus of the impact of this parasite on its hosts. These anemones may decrease cercarial transmission for many other trematode species as well. Our results stress the need for studies of parasite transmission in natural contexts rather than under simplified laboratory conditions.     

The composition of the blood of the grapsid crab, Helice crassa Dana

The ability of the grapsid crab, Helice crassa Dana, to regulate the ionic concentration of its blood in adverse salinities has been investigated. The significance of these data is compared with those for other grapsid crabs and other Crustacea.     

Osmotic and ionic regulation in Callianassa kraussi Stebbing (Crustacea: Decapoda: Thalassinidea)

Callianassa kraussi Stebbing in southern Africa has been recorded in salinities down to 1‰ Experiments suggest that because of the burrowing activities of the prawns, the substratum is unlikely to provide insulation against transient low surface salinities. Investigation of osmotic and ionic regulation in this species has shown that hyper-osmoregulation occurs in salinities below $\text{\$}\text{?}$20 ‰: hyper-osmoregulatory ability decreases in salinities below $\text{\$}\text{?}$3.5 ‰ Previous work on the genus Callianassa suggested that there was no osmo-regulatory ability in this group and a possible reason for the development of this faculty in the southern African species is discussed.     

The energy cost and efficiency of burrowing in the sandy-beach whelk Bullia digitalis (Dillwyn) (Nassariidae)

The oxygen consumption of Bullia digitalis (Dillwyn) at 15°C has been measured in the laboratory under conditions which gave rise to repeated digging cycles, and compared with oxygen uptake while the same animals were stationary. The energy cost of burrowing is calculated to be about 5 × 10^?4 Joules (2.1 × 10^?3cal) per digging cycle in a whelk whose dry tissue weight is 750 mg. The overall efficiency of the burrowing process is ≈ 6%, in contrast to the 20% efficiency which has generally been assumed for locomotory activities.     

Locomotory rhythms and burrowing habits of Penaeus semisulcatus (de Haan) and P. Monodon (Fabricius) (Crustacea: Penaeidae)

The locomotor activity of adult Penaeus semisulcatus (de Haan) and P. monodon (Fabricius) has been studied. The former was reared entirely, and the latter partly under artificial conditions. Both species display circadian activity rhythms in response to light entrainment. Light appears to be a major synchronizer, although the results indicate that feeding also has a certain synchronizing effect in starved prawns.The expression of endogenous activity rhythms in both species is affected by their substratum requirements and burrowing habits. Choice experiments show that both P. semisulcatus and P. monodon select a fine grade sand for burrowing, although the burrowing frequency of the latter species is always low. In a non-choice situation, P. semisulcatus will readily enter a coarse substratum whereas P. monodon will very seldom do so.The effects of various light regimes on the activity patterns of P. semisulcatus and P. monodon were examined and the results show that for both species an imposed long photoperiod regime (18:6 LD) induced 6-h periods of brief but intense activity, alternating with 18-h periods of almost complete inactivity. This activity pattern is discussed in relation to feeding and energy expenditure.     

Disturbance,emigration, and refugia: How the mud snail,Ilyanassa obsoleta (Say), affects the habitat distribution of an epifaunal amphipod,Microdeutopus gryllotalpa (Costa)

In the presence of the mud snail Ilyanassa obsoleta (Say), the tubicolous amphipod Microdeutopus gryllotalpa (Costa) emigrates to snail-free sediments, as demonstrated in laboratory and field experiments. Emigration occurs predominantly in the dark when the amphipod is most active. Unlike crevices, the thickness of sediments in which the amphipod is established offers no protection from snail disturbance. Emigration is shown to be caused by the disturbance generated by the snail's plowing and burrowing across the sediment surface, and not a response to a reduction in the shared microfloral food supply. The crawling and burrowing of the smaller mud snail, Hydrobia totteni Morrison, does not disturb Microdeutopus, supporting the hypothesis that relative body sizes affects the ability of bioturbators/burrowers to disturb tube-dwellers. As the burrows of Microdeutopus extend only ≈2 cm below the sediment surface, thick mud layers do not offer any refuge from Ilyanassa. However, very small solid surfaces (≈1–2 mm in relief) to which the amphipods build tubes do provide some protection from Ilyanassa. In soft-sediment benthic communities, such small structures may provide significant refuge for small epifauna and shallow burrowing infauna escaping from small-scale, biogenic disturbance.     

Molecular phylogenetic analyses of Ulva (Chlorophyta, Ulvophyceae) mats in the Xiangshan Bay of China using high-resolution DNA markers

Intertidal Ulva mats occur annually in winter and spring in the Xiangshan Bay (29°26′–29°34′ N, 121°27′–121°50′ E) of China. Thousands of tons of Ulva biomass have been harvested as edible seaweeds for human consumption for several decades in this region. This investigation was designed to quantify Ulva microscopic propagules associated with the mat, identify species composition, and to analyze intra-species relationships using three molecular markers. Phylogenetic analysis based on the nuclear encoded rDNA internal transcribed spacer region, the plastid encoded large subunit of the ribulose 1,5-bisphosphate carboxylase gene, and the 5S rDNA spacer region showed that the mat was principally composed of Ulva prolifera and Ulva flexuosa. Their propagules were detected in both the water column and sediment. Based on phylogenetic analyses of the 5S rDNA spacer region, mat samples of U. prolifera and U. flexuosa were genetically distinct from the green tide samples in the Yellow Sea and U. flexuosa samples from Jiangsu coasts, respectively, revealing that isolated geographical position of the Xiangshan Bay might result in the maintenance of a distinct Ulva population. The results demonstrate that high-resolution DNA markers have great potential in identification and discrimination at and below the species level.     

Movement,morphology, reproductive periodicity,and some factors affecting gonad production in the seastar Astrostole scabra (Hutton)

At Kaikoura, New Zealand (42°25′S: 173°42′E), tagged, immature Astrostole scabra (Hutton) usually remained within intertidal pools for <30 days. There was no seasonal vertical migration or intermixing of sub-populations. Intertidal seastars were smaller, had a thicker skeleton, and were damaged more frequently than their subtidal counterparts.The onset of sexual maturity in this species occurred coincidentally with the adoption of an exclusively subtidal habitat (20–146 m), the attainment of a radius of at least 110 mm, and a reduction in skeleton thickness. In 1975, 1976, and 1977, spawning was in late August-early September. Gametogenesis commenced in February–March. There was no seasonal inverse correlation between gonad and pyloric caeca indices.In undamaged, subtidal seastars of both sexes, gonad production was related to body size such that the volume of gonad produced by August increased linearly with respect to eviscerated wet weight. Regeneration partly suppressed gonad production, and large intertidal seastars had reduced gonad indices. The periodicity of reproductive events could not be correlated unequivocally with any physical or biotic exogenous environmental factor.     

Specific features of distribution and size indices of four poorly studied species of sculpins (Cottidae) in the Okhotsk Sea Waters off Kamchatka

Evidence on occurrence in catches and characteristic of the spatial-bathymetric distribution and size indices of four species of Cottidae—frog sculpin Myoxocephalus stelleri, brightbelly sculpin Microcottus sellaris, antlered sculpin Enophrys diceraus, and furseal sculpin Stelgistrum stejnegeri—in summer-autumn months in the Okhotsk Sea waters off Kamchatka (site from 51°15′ to 57°20′ N, depths of 11–100 m) are provided. The first three species occur mainly in the northern part of the shelf above 54° N at depths smaller than 30–40 m within a comparatively well warmed surface water mass of seasonal modification at near-bottom temperature values above 6°C at various solid grounds. Maximum catches of S. stejnegeri were recorded only at a site of the western Kamchatka shelf from 54°00′ to 54°20′ N on pebbly-stony ground in a narrow bathy-metric range of 41–60 m on the boundary between the well warmed surface water mass of autumn modification and the cold intermediate water mass at a water temperature below 2°C. Evidence on the size-weight indices of the studied species of Cottidae in trawl catches in the Okhotsk Sea waters off Kamchatka in the study period is provided.     

Seasonal thermoregulation in the burrowing parrot (Cyanoliseus patagonus)

Birds exposed to seasonal environments are faced with the problem of maintaining thermogenic homoeostasis. Previous studies have established that birds native to the Holarctic increase their Resting Metabolic Rate at different ambient temperatures (RMR_Ta) and Basal Metabolic Rate (BMR) in winter as an adaptation to cold temperature since winters are more severe, while their non-Holarctic counterparts generally decrease their winter BMR as an energy saving mechanism during unproductive and dry winter months. In this study, we examined seasonal thermoregulation in the burrowing parrot (Cyanoliseus patagonus), a colonial psittacine native to the Patagonian region of Argentina, a region with an unpredictable environment. We found significantly higher mass specific RMR_Ta and BMR in summer than in winter. Both summer and winter BMR of the species fell within the predicted 95% confident interval for a parrot of its size. Body mass was significantly higher in winter than in summer. The burrowing parrot had broad thermo-neutral zones in winter and summer. The circadian rhythm of core body temperature (T_b) of burrowing parrots was not affected by season, showing that this species regulated its T_b irrespective of season. These results suggest that the burrowing parrots' seasonal thermoregulatory responses represent that of energy conservation which is important in an unpredictable environment.     

Effect of the snail Ilyanassa obsoleta (Say) on dynamics of the amphipod Corophium volutator (Pallas) on an intertidal mudflat

We investigated interactions between two dominant invertebrate species of intertidal soft-sediment environments of the northwest Atlantic, the mud snail Ilyanassa obsoleta and the burrowing amphipod Corophium volutator, on a mudflat of the upper Bay of Fundy, Canada. Distribution of I. obsoleta on the mudflat was highly patchy and negatively correlated with density of C. volutator. Manipulation of snail density in cages showed that I. obsoleta influences C. volutator; specifically, increasing density of snails reduced density, increased patchiness in distribution, decreased recapture rates and decreased immigration of C. volutator. Ilyanassa obsoleta seems to be affecting C. volutator through an influence on survival rate and emigration rate, although temporal variation in these effects was observed. Given that both I. obsoleta and C. volutator show a preference for tide pools, an important microhabitat on mudflats, snails might have a profound impact on C. volutator population dynamics.     

Evaluation of Alternaria crassa for biological control of Jimsonweed: Host range and virulence

An isolate of Alternaria crassa (Saac.) Rands was obtained from a naturally occurring leaf-spotting disease of Jimsonweed (Datura stramonium L.) plants. The fungus was induced to sporulate and used to reproduce the disease on seedlings in greenhouse and field inoculation tests. The fungus grew best at 25–35°C, and germinated best at 25–30°C. Infectivity on Jimsonweed was reduced at temperatures below 20°C and above 30°C. In greenhouse host range studies, conidia of the fungus were highly pathogenic to Jimsonweed, moderately pathogenic to ‘Marion’ and ‘Beefsteak’ tomatoes, and non-pathogenic to several other crop and weed species representing seven botanical families. These findings indicate that A. crassa has potential as a biological herbicide for controlling Jimsonweed.     

Effects of high-temperature stress and heat shock on two root maggots, Bradysia odoriphaga and Bradysia difformis (Diptera: Sciaridae)

Bradysia odoriphaga and B. difformis (Diptera: Sciaridae) are devastating pests of vegetables, ornamentals and edible mushrooms. In Chinese chive fields, the two Bradysia species occur with similar regularities: outbreaks in spring and autumn, and population decreases in summer. Temperature may be an important factor restricting their population abundance in summer. Here, we performed a life-table study under constant high temperatures and assessed the tolerance of two Bradysia species to heat shock. Life parameters of the Bradysia species indicated slow developmental rates, and low survival rates and fecundity, when the temperature was higher than 30 °C. At 34 °C, individuals were unable to reach the adult stages from eggs. Moreover, temperatures above 36 °C showed lethal effects, decreasing their survival rates. The median lethal time (LT50) values of 4th instar B. odoriphaga and B. difformis larvae were 46.82 and 32.97 h, respectively, while the values at 38 °C were 2.12 and 1.51 h, respectively. The 4th instar larvae and pupae possessed higher thermotolerance levels than adults and eggs, indicating sensitivities to heat stress. Moreover, B. odoriphaga was more thermotolerant than B. difformis. Thus, weak thermotolerance levels may restrict their occurrences during the period of summer heat, and the difference in thermotolerance levels between the two species may be related to their regional distributions.     

Egg Placement by Anopheles gambiae (Diptera:Culicidae) as Influenced by Resting Surface Slope and Enclosure

In these experiments, oviposition by laboratory-reared Anopheles gambiae s.s. was as likely to occur from a vertical perch, as from a horizontal sitting position on a substrate of moist mud or open water. Tall cylinders with moist, dark walls provided an enclosed vertical resting surface from which An. gambiae deposited eggs. Similar numbers of eggs were deposited in these cylinders as on dark and moist horizontally-positioned ovipositional substrates. Likewise, An. gambiae oviposited equally from a vertical perch among emergent surrogate reeds vs. sitting horizontally on mud. Open ovipositional resources with exposed resting surfaces presenting 45°, 90°, and 135° angles relative to the cage floor received fewer eggs than a horizontally positioned, moist and dark ovipositional dish, even though more An. gambiae females settled on these angled resting surfaces post-oviposition. We conclude that vertical resting sites are adequate perches from which oviposition can occur if they provide high humidity and the paramount dark and wet ovipositional cues for An. gambiae oviposition.