Crustacean Hosts of the Pedunculate Barnacle Genus Octolasmis in the Northern Gulf of Mexico

A survey of live and preserved crustaceans from the northern portion of the Gulf of Mexico was conducted to investigate the colonization habits of the barnacle genus Octolasmis. In all, three crustacean orders (Decapoda, lsopoda, and Stomatopoda) comprising 43 families, 78 genera, and 122 species were surveyed. Octolasmis barnacles were observed to infest 14 families, 20 genera, and 27 species of the orders Decapoda and Isopoda. In order of decreasing frequency, the Octolasmis species encountered were O. lowei, O. forresti, O. hoehi, and O. aymonini geryonophila. The first two were found primarily in the gill chambers, the third was found mainly on external mouthparts, and the last was found exclusively on the external mouthparts, ventral pereonal and pleonal surfaces of the isopod, Bathynomus giganteus. The decapod families Pisidae and Portunidae had the highest rates of infestation, whereas the family Galatheidae (represented by six species) did not host Octolasmis. The order Stomatopoda, represented by two families (Lysiosquillidae and Squillidae), two genera, and seven species was also not infested with Octolasmis. Statistical tests confirm that octolasmids do not randomly occupy hosts, rather they appear to select a subset, generally the larger species of crustaceans

A Comparison of Reproductive Strategies among Marine Snakes

(1) Gravid females representing fourteen species of marine snakes were collected from four localities along the coast of Malaysia in 1975. The average clutch size ranged from 2.9 to 17.8 but most species had between three and seven young. The number of young produced and the size of gravid Lapemis hardwickii differed significantly at two sites in the Straits of Malacca. Eight species showed a significantly positive relationship between the number of oviducal eggs and female weight. The rate of infertility among ten species ranged from 4.5 to 20%. (2) Sex ratios in the collections varied significantly through time and between localities. Enhydrina schistosa and other species collected at Muar showed tightly synchronized annual reproductive cycles. Species at other localities appeared to have more loosely synchronized cycles. (3) A comparison of species in terms of clutch size, female weight and estimated birth weight revealed several distinct reproductive patterns that are considered in the context of r and K-selection. Hydrophis fasciatus is a small species that produced small clutches of medium sized young and it puts out the highest relative effort per embryo of any marine snake, 11 %. Lapemis hardwickii and Thalassophina viperina are large snakes which have three or four very large young. Their relative effort per embryo is high, too. Enhydrina schistosa is the largest species studied and has many medium sized offspring. Its relative effort per embryo is the lowest of any marine snakes studied (2%). The remaining species make up a loose group that falls between the group T. viperina and L. hardwickii and E. schistosa in terms of effort per embryo. In general, these species have modest sized clutches and small female weights