Essay Hypothesis and Focal Male

Submitted By taltypes
Words: 1306
Pages: 6

Formulating & testing hypothesis in Animal behaviour by observing Poecilia reticulata

Introduction.
The aim of the first practical is to make qualitative and quantitative observations, and becoming acquainted to the ways in which to observe and record data. These initial observations then need to create a hypothesis that can be tested for experimentation. The study species for this particular practical are Guppy (Poecilia reticulata).
During the practical it is necessary to make observations on the phenotype and the behaviour of Poecilia reticulata. The aim of the second practical is to carry out observations and identify sexual displays and behaviour between separated males and females by placing two fish in a separate tank and recording their behaviours, trying different treatments i.e. different male to female ratios to see if they interact more and show sexual displays then replicating these to see if they show the same results and to write a list of testable hypotheses based on observations. The aim of the third practical is to test the hypothesis that “Fish do not show a preference for shoals of different sizes” to do this place cylinders into an observation tank, different treatments of fish 4:0, 2:1 and 4:1 are then placed into the cylinders while the focal fish is in the centre which then chooses which shoal it prefers this data then needs to be recorded (total visit time, number of visits) and put onto a graph to show the visit duration. The aim of the final practical is to test the hypotheses that “male courtship will not differ as a function of female body size” to do this decide on a focal male to observe, spending a few moments identifying different behaviours, then observe for ten minutes recording how many times sigmoid and gonopodium displays were presented to the small and large female, record data onto table and add to class data this will then be used to carry out a Wilcoxon’s test.

Method.
Preliminary observations:
Set up two observation tanks
Social behaviour tanks: Height- 21cm Length- 34cm Width- 16.5cm
Reproductive behaviour tanks: Height- 44.5cm Length- 121cm Width- 38cm
Identify the differences between male and female fish (size, shape, length etc.)
Observe an individual fish and make notes on its behaviour (locomotion, behaviours, purpose?)
Observe a number of males and females. Variation between males and females? (How?)

Preliminary observations on interactions between individuals:
Place two fish in observation tank two; observe their behaviour and compare to tank one.
Observe different ratios of males to females (behaviour change, effects?)
Observe more than two fish are there any other changes? (Sexual selection, behaviour differences).
Collect quantitative data, carry out replicas to standardise data. (Any effect on results?)
Experiments on social behaviour in guppies:
Using cylinders eight centimetres in diameter with a five centimetre overlap place and secure at either end of the observation tank.
Black out the tank using black paper (this is to prevent observer impacts).
Using the ratio 4:0 place focal female in centre of tank. Let fish settle for five minutes then observe for five minutes recording the behaviour.
Complete the same observation but with a focal male.
Using the ratio 2:1 place focal female in centre of tank. Let fish settle for five minutes then observe for five minutes recording the behaviour.
Complete the same observation but with a focal male.
Using the ratio 4:1 place focal female in centre of tank. Let fish settle for five minutes then observe for five minutes recording the behaviour.
Complete the same observation but with a focal male.
Using this data then create and present it on a graph to show the visit duration.
Reproductive behaviour in guppies:
Identify which fish you are too…