one of the best things about Australia is the one of the worst things is that people don't know i get to know and help to keep the Australian bush by joining NPA. The National Parks Association of NSW 399 Pitt St Sydney . 233 3618 bushwalking • meetings • lectures • journal • working committees AUSTRAliAN NATURAl HISTORY PUBLISHED QUARTERLY BY THE AUSTRALIAN MUSEUM, 6-8 COLLEGE STREET, SYDNEY VOLUME 19 NUMBER 5 PRESIDENT, MICHAEL PITMAN DIRECTOR, DESMOND GRIFFIN JANUARY -MARCH .1978 THEY FOLLOW THEIR NOSES 142 BY R. MYKYTOWYCZ A TASMANIAN TRIASSIC STREAM COMMUNITY 150 BY MAXWELL R. BANKS, JOHN W. COSGRIFF AND NOEL R. KEMP A Rotlnese weaver works on an ikatcloth at her handloom. BIZARRE OPISTHOBRANCH DEFENCES 158 BY IAN LOCH THE QUIDDITY OF TIGER QUOLLS 165 BY GRAHAM SETTLE FISHES IN SEAGRASS COMMUNITIES 170 BY DOUG HOESE COVER: A Nudibranch (Chromodoris quadricolor) WEAVING WITH NATURE 174 exhibiting brilliant warning BY DEBORAH JARVIS AND SUZANNE STARTIN colouration. (Photo: Valerie Taylor). Annual Subscription: $6-Australia; $A7.50-other countries except New Zealand. EDITOR/DESIGNER Single copies: $1.50 ($1.90 posted Australia); $A2-other countries except New NANCY SMITH Zealand. Cheque or money order payable to The Australian Museum should be sent ASSISTANT EDITOR to The Secretary, The Australian Museum, PO Box A285, Sydney South 2000. ROBERT STEWART Overseas subscribers please note that monies must be paid in Australian currency. PRODUCTION ASSISTANT LEAH RYAN New Zealand Annual Subscription: $NZ8. Cheque or money order payable to the CIRCULATION Government Printer should be sent to the New Zealand Government Printer, BRUCE GRANGER Private Bag, Wellington. EDITORIAL COMMITTEE HAROLD COGGER Opinions expressed by the authors are their own and do not necessarily represent KINGSLEY GREGG the policies or views of The Australian Museum. PATRICIA McDONALD RONALD STRAHAN ·RECOMMENDED RET AIL PRICE IN T ERNATIONAL STANO.-.RO~ER I A L N UMe£A 0004·~ 0 141 A sugar glider, To communicate with members of their own and other insects w hose behaviour is stereotyped, but in the case of Petduru s breviceps, species, animals, like man, rely on sight, sound and higher animals with much more complex patterns of marking a co n- specific with the touch as well as on taste and smell. Chemical com- behaviour and individual differences, the pheromone secretion from a munication through taste and smell is particularly concept should be used carefully and only on the under­ gland situated on advantageous for those species which live in darkness or standing that it refers merely to olfactory communication its forehead . where silence is desirable. In animals, odour-messages between members of the same species. are the equivalent of our written language since they The odour-sensitive organs in insects are located on function even in the absence of the individual sending the antennae. Thus in the silkworm moth, Bombyx mori, them and can be long-lasting. each of the two feathery antennae possesses 10,000 Scientific interest in olfaction (smell) began about forty sensory hairs (sensilli). Each sensillium is innervated by years ago. It has increased considerably since then due to one or two receptor cells connected to centres in the three main factors. Firstly, it was found that the nervous brain. Only a single molecule of the odour is required to impulses in olfactory systems could be recorded electro­ activate a receptor cell, and the activation of two hundred physiologically. Secondly, the evolution of modern of these cells initiates a motor response. electronic technology gave chemists a range of tools, The honey bee with its ten different types of glands is a which enabled them to study materials available in only particularly good example of adaptation for chemical milligram or even microgram amounts. Finally, a strong communication. The mandibular glands in workers impetus resulted from a tremendous growth in produce a secretion which acts as an alarm signal. In the ethology-a new branch of the biological sciences queen, however, the same gland emits a 'queen dealing with comparative studies of behaviour-which substance' containing ketodecenoic acid which transmits revealed clearly the need for animals to communicate different messages depending on the recipient. Thus with one another and with their environment. when digested by workers, this substance prevents them It is not the purpose of this article nor is it possible, to from egg-laying and stops them from rearing the larvae paint a complete picture of the role of odour in the life of in a way which would produce new queens. On the animals. Only a few examples are presented here to nuptial flight, the same gland produces a vaporous sex highlight the methods of silent communication in attractant which attracts the drone and induces him to different classes of animals. copulate with the queen. It is proper to start with insects since at this stage their The gypsy moth, Porthetria dispar, was the first olfaction is best understood . Entomologists who species whose own sex attractant was exploited for its pioneered this field of work introduced the term destruction. Indigenous to Europe and Introduced to the 'pheromone', which is now so eagerly and frequently USA, It escaped from captivity and multiplied to the used and misused in references to the behavioural extent that it soon infested the whole of New England. function of smell. The word is derived from the Greek The caterpillar of the gypsy moth feeds ravenously on pherein (to transfer) and harmon (to excite). It was tree leaves causing millions of dollars wort h of damage. coined to describe an odorous substance, or substances The flightless female has to attract males in order to which initiate a response in another member of the same mate. She does it very efficiently, emanating an odour species. The response may be an immediate one in the which can lure a male from almost one kilometre away. It form of a change in behaviour, in which case reference to took a group of chemists thirty years to identify the a releaser pheromone is made, or it may produce an gypsy-moth sex attractant. They used 500 ,000 female endocrine or biochemical reaction after a longer period of abdomens to obtain 20mg of the pure attractive time-a primer pheromone. Originally, the existence of substance; it can now be synthesised and is called specific substances which release unconditional charac­ 'gyplure' . teristic responses was suggested. This may be true with Thanks to the use of 'gyplure', the gypsy moth has R. MYKYTOWYCZ is a Senior Principal Research Scientist with the Division of W ildlife Research, CSIRO. His particular interest is behaviour and the role of smell in the life of animals. 142 AUSTRALIAN NATURAL HISTORY THEY FOLLOW THEIR NOSES BY R. MYKYTOWYCZ been prevented from spreading outside the northeast less for several minutes. It has been reported that the corner of the USA. Traps are baited with the artificial sex minnow, Phoxinus laevis, after expcsure to alarm lures and insecticides are then applied to infested areas. substances, avoided a feeding area in a lake for several This monitoring system based on a chemical attractant is days. The existence of responses to fear substances has used with considerable economic benefit by fruit-growers been established experimentally under field and lab­ to prevent fruit-fly infestations of orchards. oratory conditions in many groups of animals. However, even in insects reproduction and mate The astonishing ability of Pacific and Atlantic salmon selection is not the only field in which pheromones are to return to the places of their birth after prolonged involved. A vast number of studies reveal the involve­ absences has been the subject of intensive studies. It has ment of odorous substances in such behavioural been shown that their sense of smell is involved, at least situations as the selection of food and host, aggregation, partly. To demonstrate this in the case of the silver defence, territorial marking, maintenance of social order salmon, Oncorhynchus kisutch, fish from two separate and alarm-raising. branches of a spawning stream were captured. Some The honey-bee is were deprived of the sense of smell by blocking the In vertebrates, the best example of the existence of particularly well alarm pheromones is provided by fish. Some species nostrils and released downstream together with others in equipped for chem­ possess special club cells in the epidermis which release which the sense of smell was left intact. Many individ­ ical communication. the alarm substance when the skin is injured. In their uals which could not smell, were unable to make the The queen emits odourous substances reaction to the fear pheromone, fish may flee into deeper correct choice and failed to return to their respective which affect the water, jump out of the water, seek to hide in crevices or streams. Separate streams have characteristic chemical behaviour of in turbid water on the bottom or simply remain motion- identities which are independent of seasonal changes. workers and drones. VOLUME 19 NUMBER 5 143 Odour sensitive In the perception of odours, the key role is played by reproductive state of a female even before any external organs of the moth the olfactory epithelium which in mammals, including signs of oestrus are visible. Sniffing urine is very are· located on the man, lies at the centre top of the inside of the nose close common in many mammals particularly ungulates or antennae. The I•nlarged segment of to the cribriform plate of the ethmoid bone. Placing an hoofed mammals such as goats. The sniffing of urine IS [ the antenna shows electrode in contact with the surface of the olfactory associated with a characteristic form of grimacing 1 the receptor cells epithelium or in the olfactory bulb which is another part termed , from German, · Flehmen'.