Andrew Bruce Yule

University of Aberdeen | ABDN · School of Biological Sciences

Bottom trawl estimates of densities of the portunid crab Liocarcinus depurator along the Mediterranean coast of Spain from 1994 to 2003, covering a depth range of 50–800m, were analysed using non-linear geostatistical techniques. The variation of the spatial distribution was modelled through variogram analysis using depth as a covariate. Patch size...

The current work describes the use of geometric morphometrics in the study of the portunid crab Liocarcinus depurator carapace shape variation along the Mediterranean coast of Spain. As a first step, the differences in shape induced by digitizing the carapace with either a digital camera or a flat bed scanner were investigated. Carapace shape infor...

Bottom trawl estimates of densities of the portunid crab Liocarcinus depurator along the Mediterranean coast of Spain from 1994 to 2003, covering a depth range of 50–800 m, were analysed using non-linear geostatistical techniques. The variation of the spatial distribution was modelled through variogram analysis using depth as a covariate. Patch siz...

The patterns of occurrence and density of Liocarcinus depurator along the western Mediterranean coast (from Gibraltar to Cape Creus) were measured at depths between 25 and 800 m. Bottom trawl surveys were carried out from 1994 to 2003. For analysis, the area was divided into eight geographic sectors and eight depth intervals. The highest crab occur...

Geostatistical methods have been applied to the problem of accurately mapping animal densities derived from trawl surveys. Sample data are often sparse, highly skewed in distribution and quite unlike the examples used to investigate the adequacy of the methodological options available. We analysed the data from a trawl survey of the portunid crab L...

Studies on the biometric relationships of the blue swimming crab Portunus pelagicus from Bahraini waters, have been undertaken in the present investigation in order to understand the growth pattern of this species in terms of carapace length-width (CL-CW) and carapace width-weight (CW-Wt.) relationships, in this part of the world. From the (759) ma...

Geostatistical methods have been applied to the problem of accurately mapping animal densities derived from trawl surveys. Sample data are often sparse, highly skewed in distribution and quite unlike the examples used to investigate the adequacy of the methodological options available. We analysed the data from a trawl survey of the portunid crab L...

The small-scale spatial distribution of density and biomass of the crab Liocarcinus depurator off the Ebro Delta was analysed using universal kriging (non-linear geostatistics), considering depth as an external trend. In order to understand the spatial distribution of crab size, a third variable was created from the residuals of the non-linear regr...

Liocarcinus depurator is the most abundant brachyuran by—catch from commercial trawl fisheries along the Spanish Mediterranean coast. Individuals of this species were collected from bottom trawl surveys covering the entire Iberian Mediterranean coast (from Gibraltar to Cape Creus), throughout the species’ depth distribution. Geometric morphometric...

Morphometric and shape analysis are usually performed on preserved specimens. The current paper examines the effect of two common preservation methods, freezing and alcohol, on the shape and magnitude of crab’s carapace. The carapace widths and images of the carapace of two batches of the swimming crab, Liocarcinus depurator were taken before and a...

Comparative morphology of the cement delivery apparatus of three lepadomorph barnacles indicates that the lepadid Lepas anatifera is unable to relocate voluntarily, whereas the two scalpellids Pollicipes pollicipes and Capitulum mitella can. Mean relocation speeds of up to 50 [mu]m d−1 were measured for both scalpellids, which are probably underest...

Two 30 urn tortuous path depth filters, associated with either a magnetic or non‐magnetic, but otherwise identical, fuel treatment device were placed in a tandem recirculating fuel oil system comprising a single reservoir of fuel oil (red diesel) contaminated with seawater and fuel degrading microbes. For 17 d the recirculating system, with no adde...

The benefits of optical fibre as a data transfer medium are well established and exploited within numerous current applications, where high data rates and minimal cable diameters are required. Data rate requirements in excess of 1 Gbaud, to support the transmission of advanced sensor data, are achievable through single mode optical fibre cables, wh...

The behaviour ofElrninius modestur Darwin cyprids suggests interaction between surface bacterial films acclimated to contrasting shear regimes and the range of shear rates over which observations were made. Exploratory behaviour is encouraged by filmed surfaces rather than biologically clean surfaces. Increasing shear rates encourage attachment to...

The effects of pentoses, hexoses and uronic acids upon the temporary adhesion of cypris larvae of five barnacle species from four families has been studied. A common, concentration dependent, inhibitory effect of D-glucose was observed for the five species, with maximum inhibition (to 60% of control levels) occurring at 10−8M glucose. Using Balanus...

The relative tenacity of temporary adhesion of cypris larvae of the barnacle Balanus amphitrile Darwin was measured on three substrata (polystyrene, tissue‐culture polystyrene, and glass) with and without the presence of films of the marine bacterium Deleya marina (ATCC 25374). Cyprids that were day 0 (day of metamorphosis from the sixth stage naup...

Elminius modestus specimens collected from various sites on the west coast of Britain showed differences in opercular plate dimensions. Barnacles from Birkenhead and Connah's Quay had comparatively large opercular plates which is unlikely to be related to variations in temperature and salinity, but possibly due to higher levels of pollution at thes...

The interaction between Elminius modestus Darwin cypris larvae and biofilms of Deleya marina NCMB1877 covering a range of surface types has been studied by the measurement of cypris temporary adhesion. A > 16 kDa water-soluble partial fraction of bacterial exudate significantly reduced temporary adhesion on all surfaces in a manner which was indepe...

The tenacity of cypris larvae of the barnacles (Crustacea: Cirripedia) Balanus perforatus (Bruguiere) and Elminius modestus Darwin was measured on multispecies biofilms developed under contrasting shear regimes. For both species, relatively thin, dense biofilms associated with high shear (83 s-1) afforded increased tenacity over relatively thick, l...

A link between cypris temporary adhesion and settlement has often been alluded to, but never tested. Data are presented here which confirm earlier assumptions of a correlation between increased levels of settlement and greater forces of temporary adhesion of the cypris larvae of Balanus balanoides (L.).Temporary adhesion reflects behaviour since cy...

Although hermaphroditism is universal in sessile barnacles, only a few species are known to be facultative self-fertilisers. This study tested the ability of Balanus improvisus Darwin to self-fertilise. Individuals were observed to carry well-developed ovaries and well-developed testes at the same time. Fertilisation took place and the eggs develop...

Cyprids of the barnacle Chthamalus montagui Southward were reared in the laboratory. Their preference for settlement on panels treated with con‐ or allospecific water soluble protein extracts was measured. Proteins derived from C. montagui adults promoted twice as much settlement as those from either B. balanoides or E. modeslus adults. Settlement...

Whilst the role of chemoreception in juvenile crustacean feeding behaviour has received considerable attention, the chemosensory responses of larval planktonic crustacean stages have been neglected. The present study investigated the acceptability of processed, microparticulate and microencapsulated diets and the possible role of chemoattractants f...

The effects of marine bacteria on the attachment of cypris larvae of the barnacle Balanus amphitrite were investigated in the laboratory. Initial experiments included the effect of different species of bacteria, cyprid age, and bacterial film age on cyprid attachment. Additional studies examined the substratum/bacterial film interactions and their...

Laboratory measurements of oxygen consumption were made on Penaeus monodon (Fabricius) from protozoea to adult stage at temperatures between 15 and 35C. The logarithmic relationship between weight-specific respiration rate (WRt) and temperature (T) for two size groups, Protozoea 1 (PZ1) to Postlarva 1 (PL1) and PL to adult, are given as; WRt=100.43...

Penaeus monodon (Fabricius) larvae were reared from protozoea 1 to postlarva 1 initially on unicellular algae and then on Artemia as food. At each larval stage ingestion, respiration and growth rates were measured, enabling an energy budget to be calculated for each stage and for the total development. Using the model the energy budget for the tota...

Replacement of live by artificial foods is of major importance in commercial larval culture. The results presented establish, for the first time, the practicality of rearing Penaeus monodon (Fabricius) larvae on microencapsulated diets. Using food particles of <20 μm and 40–90 μm at concentrations of between 20 and 45 μl−1, larvae of P. monodon wer...

The adhesion of the sea anemones Actinia equina and Metridium senile was tested on a variety of surfaces, and the force required to remove the anemones related to the surface area of the pedal disc in contact with the substratum. In common with many other marine organisms, anemones were more strongly attached to rough surfaces and those with high f...

The limb beat movements of Balanus (= Semibalanus) balanoides (L.) and Elminius modestus Darwin nauplii were used to study the response of the larvae to patches of microalgae. Observations were made on restrained larvae in relatively large volumes of flowing sea water. The behaviour of the larvae was recorded on video-tape and analysed, frame-by-fr...

Whereas there is a wealth of literature on the feeding of herbivorous holo-plankton, notably copepods, feeding by herbivorous larvae of benthic animals has been somewhat neglected. This paper considers the functional feeding response of veliger larvae of Ostrea edulis L., Crassostrea gigas (Thunberg) and Mytilus edulis L. fed on several micro-algal...

In a recent paper we reported on the discovery of an adhesive antennular secretion used by exploring cyprids of Balanus balanoides (L.) and hinted at its possible implication in settlement behaviour (Walker & Yule, 1984). This secretion is thought to be modified integumentary protein. Since the integumentary protein of adult B. balanoides is widely...

The force of adhesion of mussel byssus pads appears to be a function of the surface energy of the substratum, increasing with the polarity of the surface. Barnacles at the cyprid stage possess a mechanism for temporary adhesion by an antennulary attachment organ which can withstand a pull per unit surface area of several atmospheres. Associated wit...

It is conclusively shown that cyprids of the barnacle Balanus balanoides (L.) use a secretion released onto the antennulary discs for temporary attachment. This secretion does not stain with conventional histochemical techniques but was shown to be proteinaceous by staining blue in Bio-Rad protein-dye reagent normally used in protein assay. The dis...

The tenacity of the barnacle cyprids of Balanus balanoides (L.) during temporary adhesion to a variety of modified Perspex surfaces was tested using a sensitive microbalance. The Perspex panels were painted on the undersides with five colours of cellulose paint. Control measurements of the magnitude of temporary adhesion to clean slate panels were...

Techniques were developed to measure the adhesion of the barnacle Balanus balanoides (L.), over the post metamorphosis period. It was found that Balanus balanoides is capable of producing a proteinaceous adhesive material within one day of metamorphosis. This adhesive material was found to withstand applied forces of 1·7×105 Nm−2 before cohesive fa...

It was shown that warmer species exhibited higher Q10 values at the lower temperatures than did the colder water species, although the warm water species continued to swim at higher temperatures. The colder water species, Balanus balanoides and B. hameri and to a lesser extent Elminius modestus, adjust the percentage time spent swimming to the envi...

The feeding behaviour of Temora longicornis (Müller) was studied using a suction restraint technique in large volumes of sea water. Observations and records were made with a video-tape recorder and Temora cephalic limb beat movements recorded with a micro-impedance pneumograph. The classical copepod feeding swirls, shown for other calanoid copepods...

Measurements were made of the strength of temporary attachment of the cypris larvae of Balanus balanoides using a sensitive micro-balance. The strength of adhesion on arthropodin treated slate panels exceeded that on clean panels and the measured forces increased as the season progressed. The observed maximum cyprid attachment strength reached 3·8...