In Scoliodon, the exoskeleton comprises the placoid scales, embedded in the skin. Structure of a Placoid Scale: A typical placoid scale consists of mainly two parts- the basal plate and the flat trident spine. The basal plate is diamond-shaped and lies embedded in the dermis and firmly placed by Sharpey's and other connective tissue fibres. The basal plate is formed [...]
The receptor organs or sense organs of Dogfish (Scoliodon) include the paired olfactory, optic or photoreceptor, statoacoustic organs, the lateral line organs or neuromasts and the ampullae of Lorenzini. Olfactory Organs (Olfactoreceptors): The olfactory organs of Dogfish (Scoliodon) are a pair of blind olfactory sacs lying on the ventral side of the head in front of the mouth. They are [...]
In this article we will discuss about the nervous system of dogfish with the help of suitable diagrams. Central Nervous System: The central nervous system is essentially tubular and encloses a narrow central canal within the spinal cord which widens out anteriorly to form the ventricles of the brain. 1. Brain: The brain of Scoliodon is large and considerably advances [...]