Fin Movements Research Articles

Caudal Fin and Body Movement in the Propulsion of Some Fish

ABSTRACT Observations made on bream, goldfish and dace swimming in the ‘Fish Wheel’ apparatus are described. These include: An account of the complex changes in curvature of the caudal fin during different phases of the normal locomotory cycle. Measurements of this curvature and of the angles of attack associated with it are given. An account of changes in area of the caudal fin during the cycle of lateral oscillation. Detailed measurements of these changes, which may involve a 30 % increase in height or a 20 % increase in area, are given. An account of the varying speed of transverse movement of the caudal fin under various conditions and the relationship of this to the changes in area and amount of bending. Details of the way this transverse speed may be asymmetrically distributed relative to the axis of progression of the fish are given. An account of the extent of the lateral propulsive movements in other parts of the body. These are markedly different in the different species studied. Measurements of the wave length of this movement and of the rate of progression of the wave down the body are given. It is concluded that the fish has active control over the speed, the amount of bending and the area of the caudal fin during transverse movement. The bending of the fin and its changes in area are considered to be directed to the end of smoothing out and making more uniform what would otherwise be an intermittent thrust from the oscillating tail region. Some assessment is made of the proportion of the total thrust contributed by the caudal fin. This is found to vary considerably, according to the form of the lateral propulsive movements of the whole body, from a value of 45% for the bream to 84% for the dace.

The Behavior of the Pumpkinseed Sunfish, Lepomis Gibbosus (Linneaus), With Notes On the Behavior of Other Species of Lepomis and the Pigmy Sunfish, Elassoma Evergladei

The Behavior of the Pumpkinseed Sunfish, Lepomis Gibbosus (Linneaus), With Notes On the Behavior of Other Species of Lepomis and the Pigmy Sunfish, Elassoma Evergladei

The functional organization of the brain of the cuttlefish Sepia officinalis

The functional organization of the brain of Sepia has been investigated by electrical stimulation. As a result several new divisions of the brain have been made. The pedal ganglion has been shown to consist of four parts: (1) the anterior chromatophore lobes innervating the skin and muscles of the anterior part of the head and arm s; (2) the anterior pedal lobe innervating the arms and tentacles; (3) the posterior pedal lobe innervating the funnel, collar and retractor muscles of the head; (4) the lateral pedal lobes innervating the muscles of the eyes and tissues of the orbits. The palliovisceral (or visceral) ganglion, apart from the magnocellular lobe demonstrated by Young (1939), is shown here to consist of (1) a central palliovisceral lobe innervating the mantle, funnel and viscera ; (2) a pair of lobes innervating the muscles of the fins; (3) a pair of posterior chromatophore lobes innervating the muscles of the chromatophores and skin of the mantle, fin and back of the head; (4) a pair of vasomotor lobes. Because of these new divisions the three main groupings of the suboesophageal neural tissue are now referred to as the anterior, middle and posterior suboesophageal masses corresponding to the old brachial, pedal and palliovisceral divisions. The suboesophageal centres are classified as lower motor centres and intermediate motor centres, depending on the kind of response they give to electrical stimulation and their peripheral connexions. In the supraoesophageal lobes, higher motor centres and silent areas are recognized. The silent areas include the vertical, superior frontal, subvertical, precommissural and dorsal basal lobes. Of the higher motor centres the anterior basal lobe is primarily concerned with the positioning of the head, arms and eyes, particularly during movements involving changes in direction while swimming. Such manoeuvres are brought about by the anterior basal lobe control over the fins and position of the funnel. The posterior basal lobe is here shown to consist of six main divisions: (1) the sub vertical lobe; (2) the dorsal basal lobes; (3) the precommissural lobe; (4) the medial basal lobe; (5) the lateral basal lobe; (6) the interbasal lobe. The medial, lateral and interbasal lobes are higher motor centres. The lateral and medial basal lobes control movements of the chromatophores and skin; the medial basal lobe controls swimming, breathing, fin movements and various visceral functions. The interbasal lobe controls the movements of the tentacles. The optic nerves and the optic lobes, at their periphery, are electrically inexcitable. Electrical stimulation of the centre of the optic lobes evokes all the responses that can be obtained from the other higher m otor centres. The results are discussed in term s of Sanders & Young’s (1940) physiological classification of the brain. A further category intermediate motor centre is recognized. Summary lists of the responses of each lobe are given on pages 516, 520, 525.

THE PECTORAL ANATOMY OF PANTODON BUCHHOLZI PETERS (A FRESHWATER FLYING FISH) AND THE RELATED OSTEOGLOSSIDAE

Pantodon buchholzi, a small west African osteoglossid, is thought to be a freshwater flying fish. Its expanded pectoral fins and its body‐form would add credence to this supposition, whilst its pectoral musculature suggests the way in which flight could be effected.Anatomical studies on the pectoral girdle and musculature show that both are remarkably developed and are probably unique amongst the teleosts. The girdle is characterized by the hypertrophy of its mesocoracoid and correlated hyperdevelopment of certain abductor and adductor muscles. Unlike the deep abductor muscles of other fishes, those of Pantodon originate on the mesial aspect of the girdle and pass to the exterior through an enlarged coracoid foramen. The large blocks of deep abductors fill the girdle and even surround part of the pericardium. The superficial abductors are also hypertrophied and even project posteriorly away from the body‐line. The articulation of the pectoral fins is unusual since it does not allow the fins to be folded back against the body; the only fin movement possible is in the vertical plane.Apparently the pectoral musculature is highly adapted to spread and keep open the pectoral fine, at the samo time imparting a powerful dorso‐ventral motion to the fins. To this extent, Pantodon seems capable of true, flapping flight.In both its pectoral osteology and myology, and in body‐form, Pantodon differs markedly from other flying fishes. The latter, although belonging to numerous and phyletically distinct groups, all show convergent adaptations for flight.The pectoral anatomy of the related Osteoglossidæ (Heterotis niloticus and Osteoglossum bicirrhosum) is described. That of Heterotis does not differ greatly from the generalized isospondylid type, but the anatomy of Osteoglossum is intermediate between the Heterotis condition and that of Pantodon. Many characteristics of the Pantodon girdle and myology are clearly foreshadowed in Osteoglossum.The taxonomic status of P. buchholzi has long been uncertain, but the details of its pectoral anatomy and syncranial osteology clearly confirm its place in the Osteoglossidæ and suggest a relatively close relationship with Osteoglossum and Scleropages.

致死濃度以下のパラチオンが水産動物に及ぼす影響

Goldfish (Carassius auratus) and Japanese killifish (Oryzias latipes) were kept for a long time, about a month, in the water containing an insecticide, parathion (Diethyl-para-nitrcphenyl-thiophate) in various concentrations lower than its lethal value and its toxicity upon fish was observed. By the culture experiment it was known that the insecticide gave many racognizable effects upon fish even at low concentrations as 1/30 th of its 48h-TLm (median tolerance limit), i.e., the movement of gill opercula and pectoral fins of the fish was observed to decline until the above mentioned concentration of the insecticide (Fig. 2, 3). Retardness in growth of fish due to the decrease in the amount of food eaten was also apparent at these low concentrations (Fig. 4 Table 1). The results show us that the permissible concentration of parathion upon aquatic animals should be regarded as far lower than the value of 48h-TLm×0.1, which is now considered as might be permissible for general pollutants.

The Frequency Range of Mechanical Vibrations Perceived by Three Species of Freshwater Fish

C ONSIDERING the sounds which are a normal part of the environment of fishes, the extent of the range of frequency perceived, as reported in previous investigations, seems narrow. An attempt has therefore been made to determine more fully and accurately the limits of perception of some common freshwater fishes. In the literature there seems to be little doubt at present that fishes do possess the ability to perceive sound. Greater disagreement lies in the question of limits of perception, especially in the higher frequencies. Parker and Van Heusen (1917a) found that Ameiurus responded to frequencies of four to five double vibrations (d. v.) per second. Rode (1927) reported similar results. The lower limit of response of Phoxinus laevis was found by von Frisch (1936) to be between 16 and 32 d. v. per second. Parker and Van Heusen (1917b) found that eight species of fish responded by gill and fin movements to higher frequencies up to 688 d. v. per second, with best results from Ameiurus. Manning (1924) observed similar responses in the goldfish (Carassius auratus), up to 2752 d. v. per second. Stetter (1929) reported results on five species of fish as follows: Phoxinus laevis, 4645 to 6960 d. v.; Idus melanotus, 5524 d. v.; Carassius auratus, 3480 d. v.; Cobitis barbatula, 1740 to 3480 d. v.; and Ameiurus nebulosus, higher than 13,139 d. v. Von Boutteville (1935) found that the upper limits of tone perception for characids lies above 6960 d. v. Von Frisch (1936) stated that both the upper and lower limits of tonal perception in fishes that have a well-developed capacity for hearing is approximately the same as in man. Stephens and Bate (1950), though offering no experimental proof, are of the opinion that the range of hearing possibly includes all sounds in the environment from a frequency of four or five d. v. per second caused by the body movements of the fish themselves, to the supersonic vibrations caused by bursting bubbles. METHODS AND APPARATUS

«Spontane» Aktivität des Rückenmarks bei der Elritze

Blinded spinal minnows (Phoxinus laevis), fixed free from contact, show without any stimulation “spontaneous” body and fin movements. The first slight movements begin 8–10 days after transection of the spinal cord, when the cut is made at the level of the 6th or 7th vertebra or posterior to that region. When it is made near the first vertebra the movements begin within 2–3 days. In the following days or weeks their intensity grows, in most cases until the fishes exhibit quick swimming movements. Periods of swimming (up to 1 minute) alternate irregularly with periods of absolute rest. The origin of the movements is discussed. When the spinal cord is transected at the level of the dorsal fin in a (spinal) minnow that has been operated previously in the anterior region and already shows “spontaneous” swimming, tail movements reappear after 1–2 days. The changes taking place in the spinal cord after transection seem to affect all its parts equally.

THE INDUCTION OF BROODING BEHAVIOR IN THE JEWEL FISH1

Many cichlid fishes, including the Jewel Fish, Hemichromis bimaculatus, brood their eggs and young. The eggs are guarded and fanned; the young are protected against the approach of other fish. For several days after hatching, the young which stray from the school are seized by either parent and spit out among the remainder of the school. Both parents ‘call’ their young by abrupt fin movements which are made at no other time (1). Unlike rats and mice (2), the Jewel Fish, which has raised one brood, readily distinguishes between its own young and those of other species, for it will collect and guard its own young but devour foreign species introduced at the same time (1). Prolactin has been claimed to induce the brooding behavior of fowl (3) and maternal behavior in rats (4). The results obtained with the latter are by no means clear cut, and Leblond (2) has shown in mice that the “retrieving, licking and cuddling of the young, which may be considered the main features of maternal behavior, may be initiated...

Respiration as a Factor in Locomotion of Fishes

THE accepted explanation of the locomotion of fishes not in contact with some solid surface is in terms of, first, the sinuous m-ovement of the body, and, second, the movements of the various fins. The relative importance of the numerous factors embodied in these of obvious necessity differs from species to species, depending upon the degree and kind of specialization of any given form. While the present writer professes disagreement with the accepted explanations on several points as to the manner in which the known factors react on the surrounding element, it is not the purpose of this paper to attempt an overthrowing of these current conceptions, its purpose being simply that of calling attention to the existence of another factor in fish locomotion which had escaped the observation of students until discovered and called to mazy attention by Mr. Clifford MN1. Paxton of Brooklyn, New York. Mr. Paxton has invented and claimed patent rights on a strikingly novel method of propelling ships which he calls an induced stream line system. His thoughts, as developed, were the results of the contemplation of abstract hydraulic principles, but his discoveries and the developments of these principles caused him subsequently to conclude that fishes must receive locomotor benefit from the automatic operation of certain parts in accordance with one or more of the principles which he has developed for the high speed propulsion of vessels. A brief consideration of Mr. Paxton's propulsion method is necessary to a proper understanding of some of these newly discovered factors of fish propulsion.

Do Flying-Fish Fly?

I CANNOT pretend to the great experience of Mr. R. W. S. Mitchell in observations on aerial movements of the flying-fish when for a brief space he leaves his native element; but during one voyage from the Isthmus of Panama to England viâ the West Indies I lost no opportunity (of many) of watching these beautiful creatures, sometimes very close indeed to our steamer. The opinion I formed at the time and still retain was that there was constant very rapid motion of the great lateral fins whilst out of the water, so rapid, indeed, that the strokes of the fins could not be counted. From what Mr. Mitchell says, he evidently counted the strokes of the wings (pectoral fins), not by seeing the movements of these, but by the “impressions made on the oily surface of the water,” impressions apparently similar to those made by a cormorant or other diver when taking wing from the sea.