The seasonal increase in the temperature of freshwater bodies cause increase in natural food for fishes.įishes grow at faster rate at the optimum temperature, at which their appetite is high and requirement of maintenance is low. Temperature plays an important role as it affects metabolism and food consumption in fishes. However, age of fishes in captivity, i.e., in the aquarium may be expected to be more but do not exceed to 5 years.įishes show a considerable variation in their growth rate and age of sexual maturity in northern and southern waters. Many fishes that attain size of 12 inches show a life span of at least 4 to 5 years. It has been observed that generally species with large individuals seems to exhibit older age than species consists of small fish. (v) Some part of assimilated food is used for growth. (iv) Some part of assimilated food is used for maintenance of metabolism. (iii) Some part of absorbed food is excreted through the kidney, gall bladder and skin. (ii) A part of ingested food is digested and absorbed by the gut. (i) Some part of food is neither digested nor absorbed and is passed out along with faeces. Hence it is necessary to know about the fate of consumed food, which is as follows: Only a small amount of food is utilized for growth. It has been found that the total amount of food consumed is not used for growth. By comparison of food consumption and growth rate between the fish from natural habitat and the fish kept in captivity. By determining the intake of nitrogen, which helps in the growth, and the loss of nitrogen in excretion through kidney and gills.ģ. Then quantity of food present in the stomach is determined followed by estimation of rate of gastric digestion.Ģ. Samples of fish are collected from the nature. All these points indicate that these fossils are the oldest record of the family Turritellidae-by almost 30 million years-in the world.Food plays an important role in the growth of fish.įood consumption rate is estimated by the following methods:ġ. Age of the Dhosa Oolite has recently been confirmed based on multiple ammonite species. The turritelline assemblages occur only on the northeastern flank of the Jhura dome (23☂4’47.57”N, 69☃6’09.26”E). The four species are in order of abundance, Turritella jadavpuriensis Mitra and Ghosh, 1979 Turritella amitava new species Turritella jhuraensis Mitra and Ghosh, 1979, and Turritella dhosaensis new species. We here describe and/or redescribe-based on examination of more than 2600 near complete specimens-four species from the Upper Jurassic Dhosa Oolite Member of the Chari Formation in Kutch, western India, and demonstrate that they are members of Turritellidae, subfamily Turritellinae, on the basis of diagnostic characters including apical sculptural ontogeny (obtained from SEM study), spiral sculpture, and growth line patterns. Some morphological characters of the present turritelline species resemble those of mathildoids, but many diagnostic characters clearly separate these two groups. For many decades, it has been the consensus that the oldest definite representatives of Turritellidae are from the Lower Cretaceous, and that pre-Cretaceous forms are homeomorphs.

Their shell is morphologically simple, making homoplasy widespread and phylogenetic analysis difficult, but fossil and living species can be recognized based on shell characters. Turritellid gastropods are important components of many Cretaceous–Recent fossil marine faunas worldwide.

Oolite growth rate diagram