Shellfish sources

Produced by microorganism and subsequently Ingested by shellfish. Source of some red tides. ... 

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES). 

The order Mesogastropoda contains the family Conidae (400 species) whose venom apparatus consists of a barbed hollow tooth through which venom is expressed from a venom duct using a bulb as the source of pressure see Chapter 20 in this volume). The cone shells, as discussed previously, are divided on the basis of their prey species be it fish, worms, or other shellfish. 

The dietary importance of benthic invertebrates to many species of fish, birds, and mammals (Vander Zanden and Vadeboncoenr 2002) signifies their importance in the trophic transfer of MeHg and their potential relevance as biological indicators. Some benthic invertebrates (e g., oysters, clams, shrimp, crabs, and crayfish) are consumed by humans, providing a direct pathway for exposure to MeHg. In the United States, shellfish rank below fish as a source of dietary MeHg in the human population (NRC 2000 Schober et al. 2003). 

Methylmercury, which we referred to in the neurotoxicity section, occurs in fish and shellfish found in both the ocean and fresh water systems. The mercury that is the source of methylmercury arises from power plant emissions and industrial processes. Some even comes from... 

Vitamin B12 is not found in plants. The primary source is microorganisms and the usual dietary sources for humans are meat and meat products (including shellfish, fish and poultry) and to a lesser extent milk and milk products. However, normally the microorganisms in the colon provide most of the requirement. 

Although there is little information on 1,4-dichlorobenzene levels in food (lARC 1982 Oliver and Niimi 1983 Page and Lacroix 1995), it does not appear that this is an important source of human exposure. However, additional data on 1,4-dichlorobenzene levels in foodstuffs, especially commercially important fish, shellfish, and plants, would be useful to confirm this assumption. 

In this paper we summarize our recent findings on paralytic shellfish toxins in tropical waters (8-15) with new assignment of a component previously unreported. It includes the confirmation of paralytic shellfish toxins in the dinoflagellate Pyrodinium bahamense war, aompressa and bivalver exposed to the organism (, with structural elucidation of three components (9,1 ). The detailed analyses of the toxin composition of crabs (11-13) and marine snails (13,14) and confirmation of a calcareous red alga Jania sp. as the primary source of the toxins ( 15) are also described. 

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