Jasper Fish

Jasper Fish (buried 28 July 1791 at Sevenoaks, Kent) was a noted professional cricketer in the 18th century who was chiefly associated with Kent in the 1760s and 1770s.

Most of his career took place before cricket's statistical record began with regular scorecards in 1772 and he is recorded in only three major cricket matches in 1769, 1773 and 1777.

References

External sources

Fish anatomy

Fish anatomy is the study of the form or morphology of fishes. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in the living fish.

The anatomy of fish is often shaped by the physical characteristics of water, the medium in which fish live. Water is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does. The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always externally visible. The skeleton, which forms the support structure inside the fish, is either made of cartilage, in cartilaginous fish, or bone in bony fish. The main skeletal element is the vertebral column, composed of articulating vertebrae which are lightweight yet strong. The ribs attach to the spine and there are no limbs or limb girdles. The main external features of the fish, the fins, are composed of either bony or soft spines called rays, which with the exception of the caudal fins, have no direct connection with the spine. They are supported by the muscles which compose the main part of the trunk. The heart has two chambers and pumps the blood through the respiratory surfaces of the gills and on round the body in a single circulatory loop. The eyes are adapted for seeing underwater and have only local vision. There is an inner ear but no external or middle ear. Low frequency vibrations are detected by the lateral line system of sense organs that run along the length of the sides of fish, and these respond to nearby movements and to changes in water pressure.

Fish physiology

Fish physiology is the scientific study of how the component parts of fish function together in the living fish. It can be contrasted with fish anatomy, which is the study of the form or morphology of fishes. In practice, fish anatomy and physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the later dealing with how those components function together in the living fish.

Respiration

Most fish exchange gases using gills on either side of the pharynx (throat). Gills are tissues which consist of threadlike structures called filaments. These filaments have many functions and "are involved in ion and water transfer as well as oxygen, carbon dioxide, acid and ammonia exchange. Each filament contains a capillary network that provides a large surface area for exchanging oxygen and carbon dioxide. Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. In some fish, capillary blood flows in the opposite direction to the water, causing countercurrent exchange. The gills push the oxygen-poor water out through openings in the sides of the pharynx.

Scooter

Scooter may refer to:

Vehicles

Ground

Human or gravity powered

Motorized

Air

Water

Scooter (motorcycle)

A scooter or motor scooter is a motorcycle with step-through frame and a platform for the rider's feet. Elements of scooter design have been present in some of the earliest motorcycles, and motorcycles identifiable as scooters have been made from 1914 or earlier. Scooter development continued in Europe and the United States between the World Wars.

The global popularity of scooters dates from the post-World War II introductions of the Vespa and the Lambretta. These scooters were intended to provide low-power personal transportation (engines from 50 to 250 cc or 3.1 to 15.3 cu in). The original layout is still widely used in this application. Maxi-scooters, with engines from 250 to 850 cc (15 to 52 cu in) have been developed for Western markets.

Scooters are popular for personal transport, partly due to being cheap to buy, easy to operate and convenient to park and store. Licensing requirements for scooters are easier and cheaper than for cars in most parts of the world, and insurance is usually cheaper.

Diver propulsion vehicle

A diver propulsion vehicle (DPV, also known as an underwater propulsion vehicle or underwater scooter) is an item of diving equipment used by scuba and rebreather divers to increase range underwater. Range is restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed under exertion, and the time limits imposed by the dive tables to avoid decompression sickness. DPVs can have military application.

Structure

A DPV usually consists of a pressure resistant watertight casing containing a battery-powered electric motor, which drives a propeller. The design must ensure that the propeller cannot harm the diver, diving equipment or marine life, the vehicle cannot be accidentally started or run away from the diver, and it remains neutrally buoyant while in use underwater.

Application

DPVs are useful for extending the range of a diver that is otherwise restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed under exertion, diver fatigue, and the time limits imposed by the dive tables to avoid decompression sickness. Typical uses include cave diving and technical diving where the vehicles help move bulky equipment and make better use of the limited underwater time imposed by the decompression requirements of deep diving.