ISRAEL JOURNAL OF ZOOLOGY, Vol.37, 1990, pp. 51-53

ARGONAUTA ARGO- A RARE OCCURRENCE OFF THE SHORES OF ISRAEL

1 2 3 D. POPPER , A. BARASH AND B.S. GALIL 'Israel Oceanographic and Limnological Research Institute, National Center for Mariculture, P.OB. 1212, Elat, Israel; 2Department of Zoology, GeorgeS. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel; 3Israel Oceanographic and Limnological Research Institute, P.OB. 8030, Haifa and Institute for Nature Conservation Research, GeorgeS. Wise Faculty ofLife Sciences, Tel Aviv University, Tel Aviv,Israel

The paper nautilus, "Argonauta argo (Linnaeus, 1758) is a remarkable cephalopod inhabiting the Mediterranean and other warm and temperate seas. The female is lodged in a boat-shaped, unchambered shell that serves primarily as brood chamber. This thin-walled, transversely-wrinkled shell is secreted by lobular enlargements at the tips of the dorsal arms. These membranous flaps are spread over the outer surface of the shell, with suckers grasping it along the rows of carinate tubercles. The dwarf male, one twentieth the size of a female, lacks a shell. His third arm is hectocotylized, the hectocotylus consisting of a basal spermatophore reservoir and a distally flagellate sucker-bearing part. On maturation the hectocotylus detaches itself from the male and enters the mantle cavity of the female. Occasionally whole mature males are found in the shell of the female (Naef, 1923). The argonaut's distinctive form was known to the ancients, who related fanciful, though enchanting, accounts of its habits. Aristotle, in Historia Animalium (Smith & Ross, 1910), elaborates: "In between its feelers it has a certain amount of web-growth, resembling the substance between the toes of web-footed birds .... It uses this structure, when a breeze is blowing, for a sail, and lets down some of its feelers alongsides as oars." Similarly Plinius, in Natural History (Bostock & Riley, 1890), describes how "extending backwards its two front arms, it stretches out between them a membrane of marvelous thinness, which acts as a sail spread out to the winds, while with the rest of its arms it paddles along below." The mores and prejudices of the nineteenth century, reflected in Dall's (1870) description, are no less arcane: "as among more highly organized beings sometimes the gentler sex outshine their brothers in the splendor of their apparel. .. folding her arms about her [the female argonaut] is speedily arrayed in all her glory and has not shown any discontent at the old fashions since the time of Aristotle".

Accepted 17 June 1990 52 D. POPPER ET AL Isr. J. Zool.

Argonauta argo has long been known from other parts of the Mediterranean, but has not yet been reported from the southern part of the Levant basin, the nearest record being between Cyprus and Turkey (Adam, 1967)~ Ruby and Knudsen (1972), in their review of Cephalopoda from the Mediterranean east of 23° B, mention Argonauta, but offer no additional record. Records from the Red Sea are rare as well. Wulker (1920) examined several Argonauta argo shells from Kosseir in the Stuttgart Museum, and the British Museum collections include specimens of Argonauta hians (Solander, 1786) from the Red Sea and Muscat (Robson, 1932). Adam, who worked extensively on Red Sea cephalopods, mentions no further records (1942, 1960). Mienis (1980) reported three specimens from the northern Gulf of Blat. The mollusc collection at Tel Aviv University contains three partially broken egg cases collected off Appolonia at 34 fm {TAU MO 28410), off Tel Aviv at 300 fm (fAU MO 28411) and off northern Sinai at 50 fm {TAU MO 28412). Recently two specimens were added to the collection. One (Fig. 1) was collected in the Mediterranean on the waterline at Tel Shikmona, in January 1990, after a winter storm and had an egg case 10.4 em long (fAU MO 28413). Another (Fig. 2) was collected on the beach in the Gulf of Blat near the Jordanian border at Blat after a southern storm and had an egg case 9.6 em long (fAU MO 28414).

Fig. 1. ArgoMUta Argo from the Mediterranean Fig. 2. ArgoMUta Argo from the Gulf of Sea. (TAU MO 28413) Blat. (TAU MO 28414)