912 BULLETIN OF MARINESCIENCE, VOL. 30, NO.4, 1980

--. 1975. Observaciones sobre el crecimiento de tortugas marinas en cautividad, Caldasia II: 139-150, McKeown, A. 1977, Marine turtles of the Solomon Islands, Ministry of Natural Resources, Fisheries Division, Honiara, 50 pp, Prichard, P. 1969. Sea turtles of the Guianas, Bull. Fla. St. Mus, 13: 85-140. Schmidt, J. 1916, Marking experiments with turtles in the Danish West Indies. Meddr. Kommn. Havunders, (Ser. Fisk.) 5: 26 pp. Witzell, W. N. 1972. To live or not to live. Int. Turtle Tortoise Soc, J. 6: 32-35. --, 1974, The conservation of the hawksbill turtle in Western Samoa. South Pac. Bull. 24: 33- 36. --, and A, C, Banner. 1980, The hawksbill turtle, Eretmochelys imbricata, in Western Samoa. Bull. Mar. Sci. 30: 571-579.

DATE ACCEPTED: May 5, 1980.

ADDRESS: Fisheries Division, Western Samoa. PRESENT ADDRESS: National Marine Fisheries Ser- vice, Southeast Fisheries Center. 75 Virginia Beach Drive, Miami, Florida 33/49.

BULLETIN OF MARINESCIENCE, 30(4):912-914, 1980

NEW RECORD OF AEGA MONOPHTHALMA JOHNSTON (lSOPODA: FLABELLIFERA: AEGIDAE) IN THE TROPICAL WESTERN ATLANTIC

Sara-Ann F. Treat

ABSTRACT-The isopod Aega monophthalma Johnston 1834 is reported for the first time from the tropical western Atlantic at Cay Sal Bank, Bahamas. The previously known distribution included the eastern and northern Atlantic.

An adult male specimen of Aega monophthalma Johnston 1834 was obtained from a depth of 460 m at Cay Sal Bank, Bahamas, in May 1978. Prior to 1900, this species had been reported from Iceland, the Shetland Islands, Britain and Norway (Barnard, 1914). In 1901 a juvenile male specimen was discovered in deep waters off the South African coast (Barnard, 1914); subsequently, the species was reported from Denmark and Sweden (Stephensen, 1948). The most recent reference to the species was that of Dollfus (1953) who listed A, mono- phthalma among the parasites of the arctic Atlantic cod Gadus cal/arias L. Other authors have stated that the cod and shark are the usual hosts of this ectoparasitic species (Schioedte and Meinert, 1879; Sars, 1899), No record of the occurrence of A, monophthalma in the tropical western Atlantic has been found, although Richardson (1904) did note sporadic records of similar northeastern Atlantic taxa from the eastern coast of the United States and as far south as the West Indies. Aega monophthalma was discussed by Bate and Westwood (1868) and was included in the review of the family Cymothoidae by Schioedte and Meinert (1879). The species was also included in Sars' (1899) account of the Crustacea of Norway, Barnard (1914) described the South African specimen in detail; Ste- phensen (1948) gave a brief description in his review of Danish fauna. Barnard's description was particularly detailed because" ... the discovery of this northern form off the South African coast bears on the interesting question of Bipolarity" (Barnard, 1914, p. 365). The mouthparts, second pereopod, and partial ventral view of the cephal on (showing first and second antennae, and frontal lamina) SHORT PAPERS AND NOTE 9]3

Figure I. Aega monophtha/ma Johnston, male. Dorsal view. Seale equals 1.0 em. were included with his description. Dorsal and ventral views of the entire animal were given by Bate and Westwood; the illustrations in Sars' account show the dorsal view, details of the cephalon, second pereopod, and pleotelson. Dorsal views of the cephalon and pleotelson were given with Stephensen's description. The only differences between Barnard's description of the South African speci- men and the species description given by Schioedte and Meinert were in the number of articles in the first and second antennae and in the number of spines on pereopods 1-3. Barnard attributed these differences to the immaturity of his specimen, noting also that its size (23 mm long) was only three-quarters of the smallest measurements given by Schioedte and Meinert.

Aega monophthalma Johnston 1834 Figure I Diagnosis.-First two articles of first antenna enlarged, flattened; outer distal angle of second article produced, extending one-half length of third article; third article narrower than second. Frontal lamina concave, anterior margin bisinuate. Eyes very large and contiguous, covering most of dorsal surface of cephalon and extending posterolaterally into pereonite I. Terminal margin of pleotelson brack- et-shaped; surface of pleotelson excavated anteriorly with median ridge extending to apex, surface prominently granulated. Uropods subequal in length and width; posterior margin of exopod rounded, of endopod slightly emarginate. Margins of pleotelson and uropods setose, armed with small spines. Measurements.-50 mm long, 34 mm wide at widest point (pereonite VI). Cofor.-When freshly dead, pink with dark brown eyes; tips of dactyls also dark brown.

Station Data.-23°35'N, 80022'W, 460 m. R/V BELLOWSStation No.8, trawl No. 4, otter trawl. Cay Sal Bank, Bahamas, 1978 May 15. Host.-Unknown (the specimen was not attached to any fish at the time the trawl sample was sorted). Disposition.-The specimen has been deposited in the Florida International Uni- versity Museum collection, catalog No. 000110. 914 BULLETINOFMARINESCIENCE,VOL.30,NO.4, 1980

Comments.-The appearance of this specimen agrees in all respects with previous descriptions of adult males of the species, although the first two articles of the first antenna are not as enlarged as the illustration given by Bate and Westwood (1868) would indicate.

ACKNOWLEDGMENTS

This work was made possible through the Florida State University System Institute of Oceanog- raphy and has been supported in part by National Science Foundation grant DEB 76-02552 to Dr. P. A. McLaughlin. The author wishes to thank Dr. McLaughlin and Dr. W. M. Goldberg for their assistance. Drs. R. C. Brusca, R. Y. George, and G. A. Schultz critically reviewed the manuscript.

LITERATURECITED

Barnard, K. H. 1914. Contributions to the Crustacean fauna of South Africa. 3. Additions to the Marine Isopoda, with notes on some previously incompletely known species. Ann. S. Afr. Mus, 10: 362-365, pI. 31B. Bate, C. S., and J. O. Westwood. 1868. British sessile eyed Crustacea 2: 286-288. John Van Voorst, London. Dollfus, R. P. 1953. Parasites animaux de la morue atlanto-arctique Gadus cal/arias L. Encycl. BioI. (Paris) 43: 1-428, 266 figs. [not seenl Johnston, G. 1834. Aega monophthalma. Loudon's Magazine of Natural History 7: 233, figs. 43a, b, c. [not seen] Richardson, H. 1904. Contributions to the natural history of the Isopoda. Proc. U.S. Nat. Mus. 27: 28. Sars, G. O. 1899. An account of the Crustacea of Norway. Isopoda 2: 62-63. pI. 26. Bergen Museum. Schioedte, J., and F. Meinert. 1879. Symbolae ad monographium Cymothoarum. I. Aegidae. Na- turhistorisk Tiddskrift ser. 3, 12: 365-366. Stephensen, K. 1948. Storkrebs IV. Ringkrebs 3. Tanglus (Marine Isopoder) og Tanaider. Danmarks Fauna 53: 38, figs. 8 and 9. G. E. C. Gads Forlag, Copenhagen.

DATE ACCEPTED: September 13, 1979.

ADDRESS: Department of Biological Sciences, Florida International University, Tamiami Trail, Miami, Florida 33/99. PRESENT ADDRESS:Department of Biology, University of South Florida, Tampa, Florida 33620.

BULLETINOFMARINESCIENCE,30(4):914-916,1980

BACKGROUND CAMOUFLAGE: AN ADDITIONAL PARAMETER IN HERMIT CRAB SHELL SELECTION AND SUBSEQUENT BEHAVIOR

Brian L. Partridge

Numerous studies have investigated the parameters of shell morphology which influence selection by hermit crabs (Reese, 1962; 1963; Grant, 1963; Orians and King, 1964; Hazlett, 1969; 1970; Spight, 1977; Elwood et al., 1979). Shown to be involved in a hermit crab's decision are the size, weight and volume of shells. Preliminary experiments reported here demonstrate that in addition to parameters previously shown to affect shell choice the degree to which a shell blends with its background is also important. Most gastropod shells are well camouflaged in their natural habitat (Barnes, 1968; Wickler, 1968) but this camouflage would only be conferred upon the inhabitant of the shell so long as it remained in the gas-