1() ETHOLOGY OF THE ASIAN TELEOST BADIS BADIS. I. LOCOMOTION, MAINTENANCE, AGGREGATION AND FRIGHT GEORGE W. BARLOW1 Max-Planck-Institut fur Verhaltensphysiologie, Seewiesen, Obb., Germany For such a popular aquarium spe- Wolfgang Wickler. Thanks are due cies, the biology of Badis badis to Herman Kacher and Alice Boat- (Hamilton-Buchanan) is remarkably right for making the illustrations. poorly known. What little informa- I would also like to express my tion is available, mostly in aquarium gratitude to Professor Lorenz for journals, is to a large measure er- providing the facilities that made roneous. Even systematically the the research possible. species appears to have been mis- I acknowledge with pleasure that placed. I hope to show in a subse- this investigation was supported by quent paper, primarily on behavior- a post-doctoral fellowship (MF al evidence, that Badis badis has 8244) from the National Institute been classified in the wrong family of Mental Health, United States and suborder. Public Health Service. The main objective of this paper is to introduce certain aspects of TERMINOLOGY the ethology of Badis badis. The Badis badis is topics considered could stand alone, The behavior of but of more importance, they con- first broken down into units and these are given names. No claim is stitute the foundation for a series of articles to follow. The treatment made that these units correspond to of locomotion, for instance, centers Fixed Action Patterns, "acts," or "components," (see Hinde, 1959). on descriptions of movements essen- Convenience has been the rule in tial to an understanding of social displays and parental care, and their fractionating the behavior. Most of derivation, rather than emphasizing the units, however, approximate hydrodynamical considerations. It Fixed Action Patterns, or subdivi- was found practical, however, to dis- sions of them. Where pertinent, the orientation components (Lorenz and cuss some of the topics as they were completed, rather than to defer this Tinbergen, 1938) are described. The prevailing terminology is usu- to later publications. ally employed when possible, but no attempt is made to follow priority ACKNOWLEDGMENTS of usage, nor in most cases are the For critically reading the manu- sources acknowledged. In this arti- script I am indebted to William cle terms both new and old referring Childers, Konrad Z. Lorenz, and specifically to Badis badis are capi- talized. Forselius (1957) has coined 1 Present address: Department of Zoology, University of Illinois, Urbana many terms to describe behavior pat- Illinois. ters observed in anabantid fishes. In [ 175 ] 176 Transactions Illinois Academy of Science spite of the similarity of the be- seems vibratory. The phasing of the havior of the anabantids and of waves between right and left fins Badis badis, and of their presumed appears to be alternate. close relationship, I prefer using my Swimming fast is accomplished in own terminology in the treatment the normal teleost manner through of the behavior of Badis badis. lateral undulations of the body. The head appears to initiate the waves MATERIALS AND METHODS by turning almost imperceptibly to the right and left. As the waves pass Badis badis is a small (maximum posteriorly through the body they standard length about 75 mm) increase progressively in amplitude. teleost fish occurring naturally in The propulsive thrust of this type tropical Asia. The stock was ob- of movement is derived from the tained from an aquarium shop in forward component of the force pro- Munich, and had been raised in that duced by the passage of the leading city. Most of the animals reported edges of the waves obliquely through on were bred in the laboratory. The the water (Gray, 1933a). Normally fish were kept in aquaria having ca- the fish employs both methods for pacities of 30, 60, and 120 liters ; swimming ahead, sculling being im- they were thickly planted with a plemented by occasional undulations. wide variety of aquatic plants, and While swimming rapidly forward, the bottoms were covered with fine the spinous portions of the dorsal gravel. Water with a hardness of and anal fins, as well as the pelvic about DH 4-6, a pH of around 6-7, fins, are usually folded against the and a temperature of approximately body. The lobes of the dorsal and 26° C to 28° C circulated through anal fins are held loosely open and a large filter reservoir and the move in unison with the caudal fin ; aquaria. Illumination was provided together they increase the surface by 25-watt fluorescent tubes. area of the posterior end of the fish. Most of the observations were This arrangement of the fins refers made directly. Strobe-light photog- to swimming movements uncompli- raphy was employed to supplement cated by interactions with other observations. fishes, predators, or prey. LOCOMOTION Backward. The pectoral fins push water forward by means of alternate Forward. Badis badis swims paddle-like beats. On the recovery slowly in comparison to many kinds stroke, the fin is feathered, the su- of fishes. At the slowest speeds, for- perior margin leading. In a well ward thrust is provided by move- developed backing, all the other fins ments of the pectoral fins which un- are folded except the lobe of the dulate, passing vertical waves down dorsal fin. The caudal fin frequently and to the rear along the fins ; this is compressed and held to one side type of movement will be referred partially cupped ; it often beats to to as sculling. In comparison to that side, probably having a greater the slower tempo of many other steering than propulsive effect. Also, teleosts, the sculling by Badis badis the fish may feel its way in the bur- Ethology of Badis badis 177 row with the caudal fin. The loosely slowest tempos, the fish barely main- expanded lobe of the dorsal fin is tained themselves in midwater ; at brought into use as a rudder. Rarely the fastest tempos, the fish often the entire dorsal fin, as well as the contacted some firm object, as though caudal fin, may remain loosely using it as an anchor. spread, particularly when backing The tempo of the pectoral fin up is incompletely expressed. movements while Hovering seems to Hovering. The fish stands in the indicate the state of excitation of water nearly motionless. The pec- the fish. Ripe 9 9 were observed toral fins, and often the lobe of the as they approached and withdrew dorsal fin, perform sculling move- from the 8 in his burrow. In each ments. The pectoral fins tend to be instance the slowest speeds were cupped with the concave surface di- recorded when the 9 was furthest rected anteriolaterally. Presumably from the S, and had been so re- the pectorals exert a backing thrust, moved for some time. Approaching resisting the forward thrust of the produced an acceleration of the tem- opercular jets (see Breder, 1926). po. The maximum invariably was The medium and pelvic fins may be achieved when the 9 actually con- either spread or depressed. Badis fronted the f. Fleeing was followed badis spends much of its time Hov- by a gradual deceleration. Among ering. sub-adults the fastest tempos were In subsequent articles, the tempo always seen during encounters with of Hovering will be compared to other sub-adults, the slowest when those of Fanning, Digging, and unmolested and full of food. Hence Shuddering, as the origins of these the faster the tempo, apparently the behavior patterns are considered. greater the excitation. Table I lists the extreme range, and Starting. In slow starting, the median, of the tempo of Hovering fish appears to change the pitch of seen in various Badis badis. At the the sculling pectoral fins slightly, TABLE 1.—TEMPO OF PECTORAL FIN BEATS WHILE HOVERING.' Temperature Range Median Estimated Standard Length (mm.) (°C) (Beats/Sec.) (Beats/Sec.) 25 26.3 4.6-6.1 5.4 27.5 26.3 4.5-5.2 4.9 30 26.3 4.5-5.4 5.0 20 26.5 3.9-4.5 4.2 22.5 26.5 4.14.6 4.4 25 26.5 4.0-4.3 4.2 Grand Range Grand Median 3.9-6.1 5.0 The upper three sets of data were taken from three ripe 99 in aquaria with mature cre, the lower three from sub-adults in an aquarium with other sub-adults. For each fish 10 samples of 50 beats each were tallied. 178 Transactions Illinois Academy of Science directing the water current to the er control of the forward movement. rear. If a faster start is required But it is placed in a less favorable the head initiates lateral trunk un- position for the initiation of another dulations in the manner typical for beat, and also sacrifices some force. most fishes (Gray, 1933b), and the The Sickle-shape is usually used only spread pectoral fins are clapped when the fish intends to dart forward against the sides in unison. In either a short distance (at least less than case the fins take on the arrange- its own body length), but when con- ment described for Forward Swim- siderable accuracy in the course is ming. necessary. In certain situations the fish starts Sickle-shape and S-shape are two with an abrupt burst of speed. The extremes and all degrees of inter- most typical preparatory posture mediacy occur. Some of the other for a fast start in Badis badis, and postures derived from locomotory a great number of other kinds of movements are shown in Figures 1C fishes, is the sigmoid, or S-shape and 1D; these occur regularly in (Fig. 1A), an arrested swimming certain displays and will be dis- undulation.