The Spiny Dogfish Shark
By: Harrison Augustine
Shark Research Definitions
Shark External Anatomy
- First dorsal fin - it is also referred to as the cranial dorsal fin, the spine itself is supported basally by a rod of cartilage which is just right above the vertebrae.
- Second dorsal fin - a median ventral fin that is situated right between the anus and the tail fin in fishes, it actually helps them to maintain stable equilibrium.
- Caudal fin - it is a vertical fin, that is actually used for propulsion in locomotion. This fin is the tail fin.
- Pelvic fin - it is a pair of fins that are located on the underside of the fishes body, attached to the pelvic girdle and helping to control direction.
- Gill slits - a series of openings that are between the gill arches of a fish, through which water passes from any of the pharynx to the exterior, which is bathing the grills in the process.
- Snout - it is a projecting nose and mouth of an animal, especially a mammal.
- Claspers - a pair of appendages that are located under the abdomen of a male shark or ray, or even at the end of a male insect, and they are used to hold the female during copulation.
- Pectoral fin - each pair of fins situated on either side just behind a fish's head, which helps to control the directions of they're movement during locomotion.
- Lateral fin - a series of sensory pores along the head and sides of fish and some amphibians by which water currents, vibrations, and pressure changes are detected.
Shark Internal Organs
- Liver - the large lobed glandular organ located in the abdomen of vertebrates, involved in many metabolic processes.
- Heart - an organ which includes the atrium and the ventricles. the heart pumps the blood supply throughout the body.
- Kidney - organs that filter urea/waste from urine and rectum urea to the blood.
- Gallbladder - an organ that is known as the green gallbladder and sits along the right edge. When not working properly, it can be very painful.
- Pancreas - a large gland behind the the stomach that happens to secrete the digestive enzymes into the duodenum.
- Small Intestine - a part of the intestine that runs right between the stomach and the large intestine; the duodenum, jejunum, and the ileum collectively.
- Large Intestine - it is mostly know as the cecum, colon and rectum collectively.
- Pancreas - an organ located near the duodenum and lower stomach. The pancreatic secreations enter the duodenum thorugh the pancreatic tube.
- Stomach - it is an internal organ in which the major part of the digestive system occurs.
- Esophagus - the part of the alimentary canal that connects the throat to the stomach; the gullet.
- Rectum - the final section of the large intestine terminating at the anus.
- Claspers - male anatomical found in some groups of animals for mating.
- Lateral line - a system sense organs found in aquatic vertebrates used to detect movement and vibration in surrounding water.
- Gills - the paired respiratory organs of fishes, and some amphibians by which oxygen is extracted by water flourishing other surfaces within or attached to the walls of the pharynx.
Species: Spiny dogfish shark
They live about 18-24 months after winter and mating.
The spiny dogfish shark happens to stay in water between 45 - 59 degrees F. It will usually venture into brackish waters. Dogfish are mostly bottom-dwellers, dwelling in the depths from the surface down to 400 fathoms. (2,400 feet).