Internal Anatomy
1) The Digestive System
The digestive system of decapods is composed of three main regions; the foregut, the midgut and the hindgut. The esophagus, the foregut and the hindgut are derived from the ectoderm whereas the midgut is derived from the derived from the endoderm. The foregut is placed dorsally in the cephalothorax and is encircled by a large, lobed digestive gland called the hepatopancreas which almost fill the dorsal part of the thorax. The midgut and hindgut are thought to carry a variety of blindly ending tubules that are called ceca. They are located along their length in the abdominal somites.
2) The Respiratory System
S. hispidus possesses branchiae or gills as all decapods crustaceans. These gills are called trichobranchiate gills and are composed of a series of filamentous branches in numerous series around the central axis. Coral shrimp have 19 branchial exites and 7 epipods; one pleurobranch on the 3rd maxilliped; exopod on each maxilliped and a single epipod from the first maxilliped until the 4th pereiopod.
3) The Nervous system
The nervous system is composed of brain dorsally located that connect to the nerve cord, ventrally longitudinal located below the feeding canal. The brain can be further described as three subunit; the deuterocerebrum, protocerebrum and tritocerebrum. Fused pair of ganglia appear in every abdominal somites. Deutocerebral neuropils are well developed in the brain of S. hispidus. The olfactory globular and the olfactory lobe join to the hemiellipsoid bodies. Each olfactory lobe is associated with two clusters of globulli cells. The important lateral antenna 1 neuropils are divided into two lobes and the antenna 2 neuropils are great as well but more extended.
The olfactory projection neurons innervate pattern firstly target the hemiellipsoid body. A unique complex of neuropils at the caudal margin of the protocerebrum has been described as ‘the lateral protocerebral complex’. Also their eyes are reflecting superposition eyes.
4) The Reproductive system
a) Male system
The testes lie dorsally in the posterior third of the cavity in the thorax. Spermatocyte are oval, located within the testes and mature as they pass the vas deferens of the gonopore. The vas deferens conduct spermatozoid from the testes to the gonopores, also called genital apertures. That is taking place at the base of the fifth walking legs. The spermatozoa are non-motile and aflagellate.
b) Female system
The ovary is located dorsally in the cephalothorax relatively similar to where the testes are in males. Ovary is paired and its size is dependent on the age and reproductive condition of the organism. The ovary expands into the abdominal somites. The ovule transit from the ovary, down to the oviducts and escape through the gonopore located in the 3rd walking legs.
5) Circulatory System
In the posterior part of the cephalothorax, the circulatory system is placed around a bulbous dorsal heart. Through a bunch of ostria the heart receives blood. The heart is surrounded by a pericardial sac. This pericardial sac is penetrated channel like ways where deoxygenated blood return the pericardial chamber.
Reference:
Goy, J.W. (2009), "Infraorder Stenopodidea ", Crustacea, vol. 9, no. 65, pp. 215-265.
Harrison, F.W.& Humes. A.G., (1992), "Microscopic Anatomy of Invertebrates", John Wiley & Sons, vol. 10, pp, 459. |