Choice of Poecillia Reticulata

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  • Topic: Guppy, Habitat, Poecilia wingei
  • Pages : 6 (1634 words )
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  • Published : March 3, 2013
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The Choice of the Poecilia Reticulata

ABSTRACT
We documented the habitat preference in the species of fish named Poecilia reticulate, also known as guppies, to determine if there would be a difference in swimming performance and other distinguished behavior patterns. A species habitat plays the key role in its life; it’s a determinant in its sexual selection, distribution and overall behavior. Guppies that are in their natural habitats must adapt to outside threats of predation, drought and other variables that may impact their mating or food source. Our experiment tested a total of 25 guppies, each being taken from a heavily populated atmosphere and placed into two separate tanks where it was the only occupant. Would it prefer to take cover amongst the artificially placed foliage or would it stay in the open as a means to investigate its surroundings? Our hypothesis was that it would choose to take cover rather than being in the open. A reason for the covering hypothesis was that the fish may feel threatened being in the open and alone. Our hypothesis was rejected; the fish did not prefer the covered side over the barren. A possible consideration for this surprising outcome is due to the fact that these fish have been raised in a controlled environment, therefore the need to take cover from predators is unneeded. INTRODUCTION

The Poecilia reticulate are a species of fish that are accustomed to warm water habitats. They are natives of the Venezuelan freshwater streams and other adjacent Caribbean islands (Matingly, 1994). In their natural habitats, they evade potential predators by using covering from surrounding foliage and other organisms in their environment. They were first introduced in scientific research as a means of controlling the mosquito population to interrupt the spread of malaria (O’steen, 2002.) While their natural habitat provides a thorough covering from predation, it also impacts the sexual selection that is prevalent among the species.

Based on recent research, it’s been found that subdued colors occur due to natural selection because of predation, while sexual selection determines the occurrence of brightly colored males. (Putatunda, 2010). In habitats with less predatory threat, the male guppy’s color and patterns will be more attractive to the female. The intensity of predation is correlated with changes in social structure, life-history traits and the expression of male secondary sexual traits such as color patterns and courtship behavior (Endler 1995). Interactions between predation and stream characteristics, especially water velocity affects the distribution and selection of guppies (Nicoletto & Kodric-Brown 1999).

An experiment was conducted to monitor the courtship behavior and swimming performance of Trinidadian guppies in microhabitats. The experiment used guppies that were from headwater streams, where predation didn’t play a vital role in its distribution or swimming performance and males from downstream sites where predators imposed a survivorship cost on ornamental males. In its microhabitats, the males from downstream sites preferred still pools opposite the higher velocities that the headwater guppies thrived and displayed stronger courtship behavior in. In downstream sites, swimming performance was positively correlated with areas of carotenoid ornamentation. The interactions between characteristics of the physical habitat and predation pressure not only affect the distribution of guppies, but also have subtle effects on the condition-dependent traits favored by females (Nicoletto & Kodric-Brown, 2003).

Our experiment was based on the habitat preference of guppies. Since they are accustomed to living in environments where there are foliage and surrounding organisms we wanted to test, if given the choice, they’d prefer the open, barren scene opposed to one that was abundant in covering. We hypothesized that the guppies would prefer the environment that was...
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