Comparison of feeding mechanisms in two intertidal gammarideans, Hyale rupicola (Haswell) and Paracalliope australis (Haswell) (Crustacea : Amphipoda)

1983 ◽  
Vol 34 (5) ◽  
pp. 717 ◽  
Author(s):  
MA McGrouther
Keyword(s):  
Intertidal Zone ◽  
Rocky Shore ◽  
Faecal Pellet ◽  
The Body ◽  
Rock Pools ◽  
Filter Feeding ◽  
Faecal Pellets ◽  
Lower Intertidal Zone ◽  
Macro Algae

The feeding mechanisms of two rocky shore, intertidal, gammaridean amphipods are described. H. rupicola inhabits the lower intertidal zone and grazes primarily on macro-algae. P. australis inhabits rock pools of the littoral fringe. These pools are flushed with seawater only during rough seas and during periods of calm have a layer of amphipod faecal pellets covering the bottom. No macro-algae grow in these pools. P. australis is microphagous, grazing micro-algae from the rocks and from the faecal pellet layer. In addition to grazing, both species exhibit setal transfer feeding on the material cleaned from the body. P. australis also appears capable of filter feeding by an action involving only the mouthparts.

scholarly journals Do algae blooms dilute the risk of trematode infections in threespine sticklebacks?

2015 ◽  
Vol 61 (6) ◽  
pp. 991-995 ◽  
Author(s):  
Alexandre Budria ◽  
Ulrika Candolin
Keyword(s):  
Body Size ◽  
Gasterosteus Aculeatus ◽  
Infected Fish ◽  
The Body ◽  
Filamentous Algae ◽  
Intermediate Hosts ◽  
Diplostomum Pseudospathaceum ◽  
The Difference ◽  
Trematode Infections ◽  
Macro Algae

Abstract Human-induced growth of macro-algae is often assumed to increase trematode infections in fishes by increasing the abundance and condition of the parasite’s intermediate host – snails – as this can boost the release of trematode larvae, cercariae, from the intermediate hosts. However, macro-algae can also impose barriers to the transmission of cercariae and reduce infections. We investigated whether an increased growth of filamentous algae affects the transmission of Diplostomum pseudospathaceum cercariae to the threespine stickleback Gasterosteus aculeatus, a common fish in eutrophied shallow waters. We exposed sticklebacks to trematode cercariae in the absence and presence of artificial filamentous algae, and recorded effects on the proportion of sticklebacks infected and the number of encysted metacercariae per fish. No significant effect of artificial algae on cercariae transmission was detected. However, the body size and the sex of the sticklebacks were strongly correlated with the number of encysted metacercariae per infected fish, with females and larger individuals being more infected. We discuss different factors that could have caused the difference in parasite transmission, including sex-related differences in body size and behaviour of sticklebacks.

The spatial and temporal distribution of koala faecal pellets

1998 ◽  
Vol 25 (6) ◽  
pp. 663 ◽  
Author(s):  
W. A. H. Ellis ◽  
B. J. Sullivan ◽  
A. T. Lisle ◽  
F. N. Carrick
Keyword(s):  
Significant Relationship ◽  
Average Length ◽  
Temporal Distribution ◽  
Faecal Pellet ◽  
Time Of Day ◽  
Spatial And Temporal Distribution ◽  
Faecal Pellets ◽  
Pellet Production ◽  
South Eastern ◽  
Free Ranging

Faecal pellets were collected under trees used by free-ranging koalas in south-western, central and south-eastern Queensland to determine the spatial and temporal distribution of pellets with respect to the activity of koalas. Deposition of faecal pellets by koalas was analysed according to the time of day at which the tree was occupied. For free-ranging koalas, 47% of daily faecal pellet output was recovered using a collection mat of 8 × 8 m placed under a day-roost tree. The best predictor of pellet production was the presence of a koala in a tree between 1800 hours and midnight. For other periods, there was no relationship between period of tree occupancy and faecal pellet recovery. There was a significant relationship between the average length of tree occupancy and the time of day that a koala entered a tree.

scholarly journals Faecal Pellets in Deep Marine Soft Clay Crusts: Implications for Hot-Oil Pipeline Design

2011 ◽  
Author(s):  
Matthew Y-H. Kuo ◽  
Malcolm D. Bolton
Keyword(s):  
Soft Clay ◽  
Faecal Pellet ◽  
Major Constituent ◽  
Biological Origin ◽  
Near Surface ◽  
Faecal Pellets ◽  
Oil Pipeline ◽  
Average Grain Size ◽  
Time Required ◽  
Pipeline Design

In recent years, the presence of crusts within near surface sediments found in deep water locations off the west coast of Angola has been of interest to hot-oil pipeline designers. The origin for these crusts is considered to be of biological origin, based on the observation of thousands of faecal pellets in natural crust core samples. This paper presents the results of laboratory tests undertaken on natural and faecal pellet-only samples. These tests investigate the role faecal pellets play in modifying the gemechanical behaviour of clayey sediments. It is found that faecal pellets are able to significantly alter both the strength and the average grain-size of natural sediments, and therefore, influence the permeability and stiffness. Hot-oil pipelines self-embed into and subsequent shear on crusts containing faecal pellets. Being able to predict the time required for installed pipelines to consolidate the underlying sediment and thus, how soon after pipe-laying, the interface strength will develop is of great interest to pipeline designers. It is concluded from wet-sieving samples before and after oedometer tests, that the process of pipe laying is unlikely to destroy pellets. They will therefore, be a major constituent of the sediment subject to soil-pipeline shearing behaviour during axial pipe-walking and lateral buckling. Based on the presented results, a discussion highlighting the key implications for pipeline design is therefore provided.

The ecology of immature phases of Trichostrongyle nematodes: II. The effect of climatic factors on the availability of the infective larvae of Trichostrongylus retortaeformis to the host

Parasitology ◽  
1948 ◽  
Vol 39 (1-2) ◽  
pp. 26-38 ◽  
Author(s):  
H. D. Crofton
Keyword(s):  
Climatic Factors ◽  
Faecal Pellet ◽  
Cold Weather ◽  
Maximum Temperature ◽  
Infective Stage ◽  
Faecal Pellets ◽  
Infective Larvae ◽  
High Death ◽  
Maximum Temperatures ◽  
Rate Of Evaporation

1. Eggs and larvae of Trichostrongylus retortaeformis were used.2. The rate of hatching of eggs was shown to be mainly related to temperature. From November to March, when maximum temperatures were below 50° F., there was no hatching. When maximum temperatures of 50–55° F. occurred eggs hatched on or before the fifteenth day, but never during the first 8 days. Eggs hatched in 8 days or less when maximum temperatures of 60–80° F. occurred.3. When the rate of evaporation in the air was high, eggs still hatched and reached the infective stage, the grass blades reducing the rate of loss of moisture from the faecal pellet. Laboratory experiments show that eggs may not develop to the infective stage if the faecal pellets are on a grassless portion of the pasture. This is most likely to occur when the rate of evaporation is high and the temperature low.4. Hatching may be delayed by cold conditions, but some eggs remain viable for long periods and they hatch when the temperature rises. Eggs passed by the host in the autumn can survive a cold winter and hatch in the spring, but eggs passed during the coldest period die.5. During periods when the maximum temperature never exceeded 55° F., little or no migration of larvae occurred. When temperatures rose above 55° F. the number of larvae migrating increased; but rise of temperature was associated with increase in the rate of evaporation. High rates of evaporation reduced the number of larvae migrating on the grass blades.6. Some infective larvae died soon after exposure on grass plots, but a small number survived long periods. In cold weather some larvae were still alive after 20 weeks. A high death-rate occurred in warm weather. A large proportion of the larvae died during periods in which the rate of evaporation was high; in one of these periods 95% of the larvae were dead at the end of 4 weeks' exposure.7. The number of larvae on grass blades of a pasture was shown to be dependent, at any time, upon the climate at that time, and upon past conditions which had influenced hatching and survival:

Plastron respiration in the marine fly Canace

1967 ◽  
Vol 47 (2) ◽  
pp. 319-327 ◽  
Author(s):  
H. E. Hinton
Keyword(s):  
Intertidal Zone ◽  
Body Wall ◽  
The Body

The larva of the fly Canace nasica Haliday feeds on Enteromorpha in the intertidal zone. Its pupae, like those of a number of other intertidal flies, have plastron-bearing spiracular gills. The gills are unlike those of any other known Diptera in that they are modified spiracles: those of other flies are modifications of the body wall adjoining the spiracle, or of both the body wall and the spiracle. Although the spiracular gills are pupal structures, they are the respiratory organs of the adult before it emerges from the puparium.

Numbers of naked amoebae inhabiting the intertidal zone of two geographically separate sandy beaches

2000 ◽  
Vol 80 (4) ◽  
pp. 731-732 ◽  
Author(s):  
Andrew Rogerson ◽  
Fiona Hannah ◽  
Gwen Hauer ◽  
Phillip Cowie
Keyword(s):  
Intertidal Zone ◽  
Sandy Beach ◽  
Sandy Beaches ◽  
Beach Sand ◽  
Cultivation Method ◽  
Future Studies ◽  
Beach Communities ◽  
Shallow Subtidal ◽  
Lower Intertidal Zone ◽  
Naked Amoebae

Numbers of naked amoebae (Gymnamoebae) inhabiting the lower intertidal zone of two sandy beaches were estimated using a novel enrichment cultivation method. Samples were collected between June and September, 1999. Beach sand at Kames Bay, Isle of Cumbrae, Scotland contained on average 2604 amoebae cm−3 while at Dania Beach, Florida, USA, sand harboured 4236 amoebae cm−3. This is the first study to focus on the abundance of naked amoebae inhabiting a sandy beach. These numbers are higher than densities generally reported for shallow subtidal sands and show that amoebae must be considered in future studies on the dynamics of sandy beach communities.

scholarly journals Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. II. Distribution and diet

2003 ◽  
Vol 30 (4) ◽  
pp. 331 ◽  
Author(s):  
B. J. Sullivan ◽  
W. M. Norris ◽  
G. S. Baxter
Keyword(s):  
Sampling Design ◽  
Faecal Pellet ◽  
Stratified Sampling ◽  
Annual Rainfall ◽  
Dietary Composition ◽  
Low Density ◽  
Phascolarctos Cinereus ◽  
Faecal Pellets ◽  
South West ◽  
Biogeographic Region

This study used faecal pellets to investigate the broadscale distribution and diet of koalas in the mulgalands biogeographic region of south-west Queensland. Koala distribution was determined by conducting faecal pellet searches within a 30-cm radius of the base of eucalypts on 149 belt transects, located using a multi-scaled stratified sampling design. Cuticular analysis of pellets collected from 22 of these sites was conducted to identify the dietary composition of koalas within the region. Our data suggest that koala distribution is concentrated in the northern and more easterly regions of the study area, and appears to be strongly linked with annual rainfall. Over 50% of our koala records were obtained from non-riverine communities, indicating that koalas in the study area are not primarily restricted to riverine communities, as has frequently been suggested. Cuticular analysis indicates that more than 90% of koala diet within the region consists of five eucalypt species. Our data highlights the importance of residual Tertiary landforms to koala conservation in the region.

On the nutrition and metabolism of zooplankton. VIII. the grazing of Biddulphia cells by Calanus helgolandicus

1972 ◽  
Vol 52 (4) ◽  
pp. 847-861 ◽  
Author(s):  
E. D. S. Corner ◽  
R. N. Head ◽  
C. C. Kilvington
Keyword(s):  
Sea Water ◽  
The Body ◽  
Soluble Form ◽  
Food Level ◽  
Faecal Pellets ◽  
Average Value ◽  
Dietary Nitrogen ◽  
Feeding Experiments ◽  
Dietary Phosphorus ◽  
Calanus Helgolandicus

The rations removed by adult and stage V Calanus helgolandicus (Claus) feeding on large cells of the diatom Biddulphia sinensis Grev. were measured using an apparatus especially designed to keep the plant cells in suspension and estimated to reach a maximum of 1800 cells/animal/day at a food concentrationof 11,300 cells/1. A continual flow method was used to study feeding at very low algal concentrations and it was found that the animals still captured Biddulphia at a food level of only 270 cells/1.The animals in the feeding experiments were used at a very low population density (6 copepods/1350 ml.) and the maximum value found for the volume of sea water swept clear – 700 ml./animal/day - was unusually high.The maximum daily rations consumed by each animal were also high, being equivalent to 47–5 % of the body nitrogen and 46–4 % of the body phosphorus. The number of faecal pellets released by the animals increased with the size of ration captured, but the percentage of the ration lost as faecal pellets was fairly constant. In terms of dietary nitrogen the average value was 65–9% and that for dietary phosphorus 59·6%.The percentage of the daily ration of nitrogen excreted in soluble form was 266% and that of phosphorus 41–2%, these values being significantly higher than those found using unfed animals. Nearly 90 % of the nitrogen excreted by the animals, whether feeding or unfed, was in the form of ammonia. The amounts of excreted ammonia and total soluble phosphorus increased significantly when the animals fed; but the small quantities of nitrogen released in forms other than ammonia did not change.

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