Brachiopods are hard shelled marine animals which closely resemble mollusks. The rate of growth of the brachiopods is analyzed by the component growth rate at each point. Traditionally, age and growth rates have been determined by use of growth increments of especially the bivalves such as the brachiopods. However, their growth increment and their related time span are a challenge to understand. Structures of known but varying ages from relatively synchronized structures samplings were used to come with a growth curve for a brachiopod. The main aim of this paper is to analyze the growth of the brachiopods using graphical method and collected data.
The graph shows a rapid growth in the initial stages reaching more than 50% of the expected average adult length. The graph also indicates that the oldest brachiopod has the least measurement. This may be attributed to high mortality rate and decreased reproducing individuals. The growth change is constant in the first earlier stages of growth then gradually increases. This could be due early low populations which have not attained sexual maturity to multiply and also taking time to adapt to the environment.
There is followed a sudden increase in growth rate due to elevated and variable Magnesium concentration during early growth. Decrease in growth rate through ontopeny which follows is associated to the more stabilized Mg concentration which arises after sexual maturation. The hypothesis is that, the size and rate of growth decreases generally with aging. Also, the basic growth rates e may be modified leading to change of basic growth patterns which is randomly observed at various stages of development.
3). Conclusion and Discussion
The early increase in the growth rate of brachiopods is related to the higher concentrations of mineral elements and higher rates of sexual maturity. Young brachiopods are observed to experience faster growth rates compared to the older ones, which are expected to produce lower amounts of carbon isotopes. The carbon isotope values which signify the tendency of the carbon isotope compositions have remained intact at their given locality. Rates at which the brachiopods grow are quite slow and greatly dependent on the seasons and the age of the animal. When it is summer, growth is faster than when it is winter. The fully mature shell contributes to a decreased growth rate in the older brachiopods.