None of the deep-sea form is the product of the locally evolved race, but they are simply adapted migrants from the lesser depth. Beyond the light zone green plants are totally absent, i.e., ecologically, no producer is present in deep-sea. In ice cold water, time for embryonic development increases. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. This layer includes shells of foraminifera’s and other organic material and ranging from 9000 – 15000 ft. Actually, environmental factors in deep seas are uniform from ocean to ocean.
As vision becomes nil, tactile organs are highly developed. As a rule there are simplified colours among deep-sea animals. The oozes are of following types. Deep sea is characterized by a set of environmental conditions, which in turn determine the adaptations of deep-sea forms. The term hadal zone is used to designate the perpetually cold and dark supreme depths of the ocean. Because upper predators cannot see a black animal in black background. Ideally, high pressure in the deep sea should crash the sea... Holding The Breath For Hours. Of all the oceanic zones, light penetrates only into the euphotic zone; the remaining zones are aphotic or devoid of light (bathyal, abyssal and hadal zones). Beyond 12000 ft Radiolarian and Diatom oozes are evident. on stiff elongate fin rays (Fig 2.4). Long feelers and slender attenuations of the fins act as a tactile organ. Answer Now and help others. The animals are frail and weak and their body is thin and flabby. Ancient zoological forms are rare in deep-sea and this indicates that deep-sea fauna includes recent forms only. Correlated with soft substratum, many of the deep-sea animals have long appendages, abundant spines, stalks or other means of support, as illustrated by tripod fish, lampshells and crinoids. Sea bottom is so uniform in physical conditions that virtually there are no environmental barriers. It is due to inability to accumulate calcium within the tissues in absence of sunlight. Convergent type of evolution is only evident due to specific ecological condition. Uncared eggs in water results in predation, which forces some of the deep-sea animals to become viviparous. So there is endless darkness in deep-sea. Due to extreme pressure the bodies i deep-sea fish and other animals are very much compressed. The atmospheric pressure at sea level is about 7 kg/sq inch. It is supposed that dorsoventrally compressed body appears due to high pressure on the body surface. Before sharing your knowledge on this site, please read the following pages:
It is also called as ‘king of Herrings’. In this study, we report the com Sometimes decomposers, like bacteria and fungus are also used as food. Vertebrates possess un-calcified or weakly calcified skeleton. In this animal pelvic fins and scales are absent, colour is black, the fin rays are tipped with luminous organs to attract the pray. Perhaps these appendages are very useful in the darkness and serve for contact reception, or compensate for the difficulties of vision.Welcome to BiologyDiscussion! In some deep-sea fishes the retina is composed of a number of tiers of rods, presumably arranged to absorb all the limited light that enters the eye (Nicol, 1989). Oxygen content is comparatively low (3.29 – 5.9 c.c/litre of water), because there are no producers, which generally contribute oxygen during day-time. As no sunlight reaches this layer of the ocean, deep sea creatures have adapted with reduced eyesight, having very large eyes for receiving only bioluminescent flashes. The organic remains are known collectively as oozes. The distance to which light penetrates varies with the angles of the sun rays and the clarity of the water. This increases enormously to about 1 ton/sq inch for every 6000 ft. Introduction to Deep Sea Adaptation: Usually lightless sea bottom is referred to as deep sea, i.e., from lower limit of littoral zone (200 metres deep) to the ocean floor. In some other deep-sea fishes, eyes are very small as they are of little apparent use, and still others are without eyes.Many deep-sea animals produce their own light by means of luminous organs, e.g., lantern fish. Their hearts are very small, they have very little red muscle and low haematocrit values.Some deep-sea fishes exhibit greatly enlarged eyes or the so-called telescopic eyes, which are highly effective in visioning lights of very low intensity. It possess short nose and elongated shark-like body (Fig. Because of lack of cues like light and temperature change, it was once thought that there was no seasonality in the deep sea, but this is not so. Others have either telescopic eyes or bear eyes like concave mirrors. Some are even viviparous and produce young ones in large number. Below the limit of disturbance caused by the storm wave, i.e., about 600 ft. and below the average depth of the tidal action all movements of sea wave are exceedingly slow.