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Jew jewels


flexo

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Below is a photo of the jewels I took out of the jew yesterday have also got some out of pearl pearch.

I was having a discussion with brian (ellicat} today and promted some research below is taken from wikipedia.

Finfish (class Osteichthyes) have three pairs of otoliths – the sagittae (singular sagitta), lapilli (singular lapillus), and asterisci (singular asteriscus). The sagittae are largest, found just behind the eyes and approximately level with them vertically. The lapilli and asterisci (smallest of the three) are located within the semicircular canals.

The shapes and proportional sizes of the otoliths vary with fish species. In general, fish from highly structured habitats such as reefs or rocky bottoms (e.g. snappers, groupers, many drums and croakers) will have larger otoliths than fish that spend most of their time swimming at high speed in straight lines in the open ocean (e.g. tuna, mackerel, dolphinfish). Flying fish have unusually large otoliths, possibly due to their need for balance when launching themselves out of the water to "fly" in the air. Often, the fish species can be identified from distinct morphological characteristics of an isolated otolith.

Fish otoliths accrete layers of calcium carbonate and gelatinous matrix throughout their lives. The accretion rate varies with growth of the fish – often less growth in winter and more in summer – which results in the appearance of rings that resemble tree rings. By counting the rings, it is possible to determine the age of the fish in years.[2] Typically the sagitta is used, as it is largest,[3] but sometimes lapilli are used if they have a more convenient shape. The asteriscus, which is smallest of the three, is rarely used in age and growth studies.

In addition, in most species the accretion of calcium carbonate and gelatinous matrix alternates on a daily cycle. It is therefore also possible to determine fish age in days. This latter information is often obtained under a microscope, and provides significant data to early life history studies.

By measuring the thickness of individual rings, it has been assumed (at least in some species) to estimate fish growth because fish growth is directly proportional to otolith growth. However, some studies disprove a direct link between body growth and otolith growth. At times of lower or zero body growth the otolith continues to accrete leading some researchers to believe the direct link is to metabolism, not growth per se. Otoliths, unlike scales, do not reabsorb during times of decreased energy making it even more useful tool to age a fish. Fish never stop growing entirely, though growth rate in mature fish is reduced. Rings corresponding to later parts of the life cycle tend to be closer together as a result.

Age and growth studies of fish are important for understanding such things as timing and magnitude of spawning, recruitment and habitat use, larval and juvenile duration, and population age structure. Such knowledge is in turn important for designing appropriate fisheries management policies.

The composition of fish otoliths is also proving useful to fisheries scientists. The calcium carbonate that the otolith is composed of is primarily derived from the water. As the otolith grows, new calcium carbonate, usually aragonite but sometimes vaterite, crystals form. As with any crystal structure, lattice vacancies will exist during crystal formation allowing trace elements from the water to bind with the otolith. Studying the trace elemental composition or isotopic signatures of trace elements within a fish otolith gives insight to the water bodies fish have previously occupied. The most studied trace and isotopic signatures are strontium due to the same charge and similar ionic radius to calcium; however, scientists can study multiple trace elements within an otolith to discriminate more specific signatures. A common tool used to measure trace elements in an otolith is a laser ablation inductively coupled plasma mass spectrometer. This tool can measure a variety of trace elements simultaneously. A secondary ion mass spectrometer can also be used. This instrument can allow for greater chemical resolution but can only measure one trace element at a time. Dr. Steven Campana is one of the leading researchers in the study of otolith trace elemental and isotopic composition. The hope of this research is to provide scientists with valuable information on where fish have traveled. Combined with otolith annuli, scientists can add how old fish were when they traveled through different water bodies. All this information can be used to determine fish life cycles so that fisheries scientists can make better informed decisions about fish stocks.

Hope you find this interesting

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