Reference: Binl. Bull 187: 363-372. (December, An Ethogram of Body Patterning Behavior in the Squid Loligo vulgaris reynaudii on Spawning Grounds in South Africa ROGER T. HANLON 1 , MALCOLM J. SMALE 2 , AND WARWICK H. H. SAUER 2 'Marine Biomedical Institute, University of Texas Medical Branch, Galveston, Texas 77555-1 163, and 2 Port Elizabeth Museum. P.O. Box 13147, Humewood 6013, South Africa Abstract. Squids are capable of a high degree of visual signaling, most of which is expressed through the neurally controlled chromatophore organs in the skin. An accurate catalog (or ethogram) of these signals is an essential pre-requisite to quantified behavioral analyses and experi-mentation. Body patterns such as those described here may also be useful for distinguishing between morpho-logically identical species or subspecies of commercial importance. The natural behavior of Loligo vulgaris rey-naudii on spawning grounds was filmed by divers, and the body patterning repertoire was described in detail; 23 chromatic components, 4 postural components, and 9 locomotor components of body patterning were observed and correlated with different types of behaviors. Most of the chromatic components were expressed during intra-specific behaviors (e.g., agonistic behavior among males, courtship, mating) and, to a lesser extent, during inter-specific interactions with fishes. Several of the most basic types of body patterns are described, the most distinctive of which are Lateral Display and White Flashing used between males in agonistic contests. This species is com-parable to other Loligo spp. in its complexity of body patterning behavior. Introduction Cephalopods have evolved a chromatophore system unique in the animal kingdom: because the pigmented cells in the skin are under neuromuscular control, skin color and pattern can change rapidly, resulting in a high diversity of appearances in individual animals. Much of the behavior of cephalopods is expressed through these Received 3 February 1994; accepted 22 September 1994. pattern and color changes of the body, which convey visual signals to conspecifics. predators, and prey (e.g., Moynihan and Rodaniche, 1982; Hanlon and Messenger, in press). These "body patterns" are made up of chromatic (i.e., color), textural, postural, and locomotor components (cf, Packard and Sanders, 197 1; Packard and Hochberg, 1977; Hanlon, 1982; Hanlon and Messenger, 1988). Chromatic components are discrete neural entities, just as postural, locomotor, and textural components are. That is, the expression of Dark head and arms, for example, represents the selective neural excitation of motor neurons in the CNS that control the expansion of all chromatophores on the head and arms. A wide variety of body patterns can be exhibited by each individual of each species; patterns are not only species-specific, some are also sex-specific. Our aim in this paper is to describe an ethogram for the commercially important squid Loligo vulgaris rey-naudii. An ethogram is a catalog and description of be-haviors and is used as the basis for studying behavior. In cephalopods, the development of a system of names for the components of body patterning, combined with care-ful illustration and description of each one, is mandatory for at least three types of studies: (a) accurate and quan-titative analyses of behavior (e.g., Moynihan and Roda-niche, 1982; DiMarco and Hanlon. in prep.; Hanlon and Messenger, unpub.), (b) developing taxonomic keys to species identification (Hanlon, 1988; Roper and Hoch-berg, 1988), and (c) comparing conserved characters of chromatic expression that can aid phylogenetic studies (e.g., Moynihan, 1985; Hanlon, 1988; Burghardt and Gittleman, 1990). Loligo vulgaris reynaudii (D'Orbigny) attains average adult sizes of 23 cm mantle length for females and 32 cm 363
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