Historical knowledge of sharks: ancient science, earliest American encounters, and American science, fisheries, and utilization

In western civilization, the knowledge of the elasmobranch or selachian fishes (sharks and rays) begins with Aristotle (384–322 B.C.). Two of his extant works, the “Historia Animalium” and the “Generation of Animals,” both written about 330 B.C., demonstrate knowledge of elasmobranch fishes acquired by observation. Roman writers of works on natural history, such as Aelian and Pliny, who followed Aristotle, were compilers of available information. Their contribution was that they prevented the Greek knowledge from being lost, but they added few original observations. The fall of Rome, around 476 A.D., brought a period of economic regression and political chaos. These in turn brought intellectual thought to a standstill for nearly one thousand years, the period known as the Dark Ages. It would not be until the middle of the sixteenth century, well into the Renaissance, that knowledge of elasmobranchs would advance again. The works of Belon, Salviani, Rondelet, and Steno mark the beginnings of ichthyology, including the study of sharks and rays. The knowledge of sharks and rays increased slowly during and after the Renaissance, and the introduction of the Linnaean System of Nomenclature in 1735 marks the beginning of modern ichthyology. However, the first major work on sharks would not appear until the early nineteenth century. Knowledge acquired about sea animals usually follows their economic importance and exploitation, and this was also true with sharks. The first to learn about sharks in North America were the native fishermen who learned how, when, and where to catch them for food or for their oils. The early naturalists in America studied the land animals and plants; they had little interest in sharks. When faunistic works on fishes started to appear, naturalists just enumerated the species of sharks that they could discern. Throughout the U.S. colonial period, sharks were seldom utilized for food, although their liver oil or skins were often utilized. Throughout the nineteenth century, the Spiny Dogfish, Squalus acanthias, was the only shark species utilized in a large scale on both coasts. It was fished for its liver oil, which was used as a lubricant, and for lighting and tanning, and for its skin which was used as an abrasive. During the early part of the twentieth century, the Ocean Leather Company was started to process sea animals (primarily sharks) into leather, oil, fertilizer, fins, etc. The Ocean Leather Company enjoyed a monopoly on the shark leather industry for several decades. In 1937, the liver of the Soupfin Shark, Galeorhinus galeus, was found to be a rich source of vitamin A, and because the outbreak of World War II in 1938 interrupted the shipping of vitamin A from European sources, an intensive shark fishery soon developed along the U.S. West Coast. By 1939 the American shark leather fishery had transformed into the shark liver oil fishery of the early 1940’s, encompassing both coasts. By the late 1940’s, these fisheries were depleted because of overfishing and fishing in the nursery areas. Synthetic vitamin A appeared on the market in 1950, causing the fishery to be discontinued. During World War II, shark attacks on the survivors of sunken ships and downed aviators engendered the search for a shark repellent. This led to research aimed at understanding shark behavior and the sensory biology of sharks. From the late 1950’s to the 1980’s, funding from the Office of Naval Research was responsible for most of what was learned about the sensory biology of sharks.

A modern pollen record from the central Gulf of California

As one facet of an effort to tie the pollen record of central Gulf of California deep cores to modern analogs, pollen was analyzed in the uppermost 150-200 years of varved core 7807-1410 taken nearby. Sampling at 2- to 8-year resolution yielded a noncomplacent record, suggesting pollen in these sediments may be a potential high resolution proxy record of short-term climatic events. The pollen spectrum as a whole matches that of upper-most DSDP Site 480 (means of all samples). Lack of a ratio or influx shift following damming of local rivers and a surplus of low-spine Compositae pollen relative to mainland sites support Baumgartner's theory that terrigenous influx to the site is largely aeolian and also suggest that a significant fraction of the pollen influx may come from Baja California.

Progress of modern aquaculture

The development of the aquaculture industry worldwide is discussed in detail with respect to activities conducted by various international organizations, considering in particular the leading role played by the FAO and its regional agencies. A brief examination is also made of the current situation regarding the industry in India and the potential for further development and improvement.

Y-chromosome haplotype distribution in Han Chinese populations and modern human origin in East Asians

We investigated the distribution of Y-chromosome haplotype using 19 Y-SNPs in Han Chinese populations from 22 provinces of China. Our data indicate distinctive patterns of Y chromosome between southern and northern Han Chinese populations. The southern po

Y-chromosome evidence for no independent origin of modern human in China

East Asia is one of the few regions in the world where a large number of human fossils have been unearthed. The continuity of hominid fossils in East Asia, particularly in China has been presented as strong evidence supporting an independent origin of mod

African origin of modern humans in East Asia: A tale of 12,000 Y chromosomes

To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites.

Y chromosome evidence of earliest modern human settlement in East Asia and multiple origins of Tibetan and Japanese populations

Background: The phylogeography of the Y chromosome in Asia previously suggested that modern humans of African origin initially settled in mainland southern East Asia, and about 25,000 30,000 years ago, migrated northward, spreading throughout East Asia. H