Tigriopus Californicus Essay, Research Paper

Tigriopus californicus is an amazing little marine crustacean that is classified as a Harpactacoid copepod. Harpactacoid meaning it?s class, and copepod meaning its order. Because of its size and abundance, T. californicus is commonly regarded as the insect of the sea. This creature is generally very small, from 1-3 mm in size as adults. They are cylindrically shaped, and have a segmented body (head, thorax, abdomen) though no noticeable division between body regions (Powlik 1966). Each segment of the body has a pair of legs. They use their ‘legs’ to propel themselves through the water in short rapid jerks. They have 2 pairs of long feathered antennae, a chitin us exoskeleton and a single eye in the middle of their head, this simple eye can only differentiate between light and dark.

T. californicus is found from Alaska to Baja in small, shallow tidepools and tidal flats in the upper spray zone where they cannot avoid the full effect of visible and ultraviolet (UV) radiation. Individuals assemble in areas of lower radiation at midday, yet have no preference to the intensity of light at dawn and dusk (Hartline and Macmillan 1995). These tiny arthropods inhabit all types of marine sediments from sand to fine mud and ooze. Along with plankton, T. californicus eats microscopic algae, protists, bacteria, diatoms, algae and microbes (McGroarty 1958). When the concentrations of the species in their habitats are high, T. californicus will turn to cannibalism for a food source. The nautilus eye present in the species is rich with fatty acids and provides a good food source for the animal.

In reproduction, the female produces clusters of eggs that she carries in one or two egg sacs that are attached to her abdomen. Once hatched, The T. Californium? life cycle has quite a few stages. The first being six naupliar (young) stages lasting 4 ? 10 days. Next come the 6-copepodite stages (7-14 days for the first 5 stages) ending in the last stage where T.californicus is a sexually mature adult. Adults then live from 40 ? 90 days after the stages are complete (Rickets and Calvin 1985).

An abiotic factor affecting growth of T. californicus is the concentration of salinity of the seawater. It can range from 35ppt too much higher salinity concentrations. The concentration of UV radiation also affects t. californicus. They tend to stay in places of low concentration of UV rays when the sun is the strongest. Too much UV radiation may cause growing defects in the animal.

Lab conditions necessary for the maintenance of T. californium are a salinity of about 35 ppt (salinity of regular seawater), a constant room temperature, and low light source. Also a good high definition microscope is necessary to monitor the creatures to make sure they are in a good state.

T. californium? are a component of zooplankton and are eaten by many organisms, including mussels, fish and fish larvae, squid, sea birds, and mammals (like baleen whales and some seals) (Powlik 1966). They usually stay to themselves in the seawater and do not interact with other organisms except for when they are using microorganisms as a food source. The only time that they interact with their own species is for mating. First a male will insert a spermatophore into a female, then the male will guard his female for the time necessary for the spermatophore to release its contents into the female. This guarding shows that the males want to secure paternity. Other interactions with it?s own species happen when there are high concentrations of the species in a small area. T. californicus will turn on it?s own species and resort to cannibalism as mentioned above.