The Grassholme Channels

The design and construction of four experimental channels at Grassholme reservoir in Teesdale, County Durham (UK) are briefly described. The problem of obtaining valid replication between channels is examined using published data obtained for previous experiments in the channels. It is concluded that replication may be obtained by careful experimental design. The limitations of the existing configuration of pipework and channel design are discussed and solutions suggested. Finally a list of the main components of the channels and suppliers is appended. Alternative materials and suppliers could well be found for most items. (PDF contains 23 pages)

Calibration of Grassholme Channels, 1982

Adjustment of experimental channels to give any specified pattern of water depth or velocity is complex and tedious because it involves a number of variables. Since some variables are not controllable and variables may interact, valve settings of the Grassholme channels were initially determined on an ad hoc basis to suit individual experiments. This method was used during 1982 but additional observations were made in order to gain more detailed understanding of the channel system and, as far as possible, to develop a guide to future short-cuts in attaining suitable channel settings for any given purpose. This report describes calibration of the Grassholme channels (using water of the Grassholme Reservoir) for the biological experiments of spring - summer 1982. The main variables that are discussed are valve turns and discharge and velocity and depth. It also seeks to establish relationships which will be of value in future managment of the channels for experimental purposes.

Experiments on downstream movement of recently emerged trout and salmon parr in Grassholme channels, 1983-1985

A number of authors have described the manner in which young salmonids, soon after emergence from the gravel, set up and defend territories. This leads to mortality or downstream displacement of the individuals which are unable to acquire territories and is widely accepted as the main method of population regulation amongst young salmonids. In some field experiments the fish were constrained in screened reaches and the option of downstream dispersal for the surplus fry was thus excluded. In order to explore some aspects of downstream dispersal more closely under conditions which gave more control than is obtained in a natural stream, four experimental channels were set up at Grassholme reservoir in Teesdale. The report describes the results of investigations on the timing and rate of downstream movement of young brown trout (Salmo trutta L.) and Atlantic salmon (Salmo salar L.) out of experimental channels, with special reference to the effect of water velocity on the rate of ”emigration”.

Characterisation of neurons in the pedal ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

To characterise central neurons in the pedal ganglia of both male and female green lipped mussel, Perna canaliculus immunohistochemical techniques were used. Mollusc antibodies were used against neuropeptides and neurotansmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a, promising tool for further characterisation of neurosecretory cells, and to isolate an'tl characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.

Neurons characterization in the cerebral ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

Immunohistochemical techniques were used to characterise central neurons in the cerebral ganglia of both male and female Perna canaliculus. We used mollusc antibodies raised against neuropeptides and neurotransmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a promising tool for further characterisation of neurosecretory cells, and to isolate and characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.