![]() ![]() If the embryo’s electroreceptors detect the presence of a predatory fish in the vicinity, however, the embryo stops moving (and in so doing ceases transmitting electric currents) until the fish has moved on. The embryos keep their tails in constant motion so as to pump water and allow them to breathe through the egg’s casing. ![]() Young ray embryos develop inside egg cases that are attached to the sea bed. Long before citizens’ band radio users first had to yell “Get off my frequency!” at hapless novices cluttering the air waves, at least one species had found a way to peacefully and quickly resolve this type of dispute.Į Electroreception can also play an important role in animal defences. Doing so prevents their electroreception faculties from becoming jammed. When two such electric fish meet in the ocean using the same frequency, each fish will then shift the frequency of its discharge so that they are transmitting on different frequencies. Active electroreception has a range of about one body length – usually just enough to give its host time to get out of the way or go in for the kill.ĭ One fascinating use of active electroreception – known as the Jamming Avoidance Response mechanism – has been observed between members of some species known as the weakly electric fish. This can help them identify whether another creature is prey, predator or something that is best left alone. Active electroreceptors can differentiate between the various resistances that their electrical currents encounter. ![]() These can be used for mating signals and territorial displays as well as locating objects in the water. Animals with active electroreception possess bodily organs that generate special electric signals on cue. While all animals (including humans) generate electric signals, because they are emitted by the nervous system, some animals have the ability – known as passive electroreception – to receive and decode electric signals generated by other animals in order to sense their location.Ĭ Other creatures can go further still, however. This ability is only found in aquatic or amphibious species because water is an efficient conductor of electricity.ī Electroreception comes in two variants. Without specialised equipment humans would be lost in these deep sea habitats, so how do fish make it seem so easy? Much of this is due to a biological phenomenon known as electroreception – the ability to perceive and act upon electrical stimuli as part of the overall senses. Sounds, too, are garbled and difficult to comprehend. You should spend about 20 minutes on Questions 1–13, which are based on Reading Passage 1 below.Ī Open your eyes in sea water and it is difficult to see much more than a murky, bleary green colour. Our higher level partners and their success stories.IELTS registration partners and partnership programmes.How to become an IELTS recognising organisation.Free online IELTS Speaking practice tests.Free online IELTS Writing practice tests.Free online IELTS General Training Reading practice test - paper.Academic Reading test 2 - section 3 practice test.Academic Reading test 2 - section 2 practice test.Academic Reading test 2 - section 1 practice test.Academic Reading - section 3 practice test.Academic Reading - section 2 practice test.Academic Reading - section 1 practice test.Free online IELTS Academic Reading practice test - paper.Free online IELTS Reading practice tests.Free online IELTS Listening practice tests.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |