CHAPTER 2 LITERATURE REVIEW 2.1. The larval fish stages Fish larvae are part of the fauna that eat smaller organisms. According to Leis and Ewart, (2000) they characterize larval stage to end with the fulfillment of full outside quantitative feature characters, the entry of any mobile structure. For the larval stage according to Termvidchakorn and Hortle, (2013) the larval stage can be divided into three which are yolk sac stage, pre-larval stage and post larval stage; whereas according to Leis and Ewart, (2000) the larval stage is divided into segment that outlined by formation of the caudal fin and flexion on the notochord. Ahlstrom and Ball, (1954) stated that the terminologies of the development stage of larval fish divided into yolk
Cephalopoda Introduction: Invertebrate animals which belong to mollusks which means “head foot” and characterized by large head and modified feet. This group includes octopuses, squid, cuttlefish and nautiluses. Members of cephalopods are characterized by their ability to quick change their color as well as changing the texture and shape of their bodies as a means of camouflage. Today there are about 800 living marine species of cephalopods which are found in all of the world’s oceans, from the tropics to the near freezing water at the poles. Description: The name cephalopods which means head-armed were given this name because these animals have several arms around their protruding mouth.
They have well-developed and symmetrical gills over which drawn water flows. The flow of water carries the waste and reproductive products. Movement: Although abalones occur in the same place, they may use their muscular foot with its suction power to move, cling and stay tight with the substrate surfaces. Feeding habits: In nature, abalone eats marine algae with a particular preference to large brown algae such as giant kelp and other kelp species. While juvenile abalone grazes for algae, diatoms and bacterial films, adults rely on drift algae, and if food becomes scares, they move after their food.
They inhabit tropical ocean regions (Deep Sea Dragonfish. (n.d.)). They have unique structures to them that they are known for like their large sharp teeth with a protruding jaw and a long thread-like expansion from their epidermal layer at the base of their chin called a barbel (Spinal gap of barbeled dragonfishes mystery solved, 17 August 2010). There are 28 genera and more than 292 different species of dragonfishes (STOMIIDAE, in Fishes of Australia, 2012). One of the Genus is Opostomias which has two known species, Opostomia micriprius
A sharks diet is very interesting. The biggest sharks eat baby fish, shrimp, plankton, and many tiny animals. Some sharks eat bony fish, squid, and can also be cannibalistic. They usually feed on smaller sharks. Great White sharks eat fish, and as they grow start to eat seals and walrus.
Echinodermata and Mollusca is the two common phylum in the kingdom Animalia. Echinodermata consist of five large classes which are, class Crinoidea, example feathers star, class Asteriodea, example star fish, class Ophiuroidea example, brittle star, class Echinoidea, example sea urchins and the class Holothroidea, example sea cucumber. Phylum Mollusca consist of six major classes, which are Monoplacophora, Gastropoda, Cephalopoda, Polyplacophora, Scaphopoda and the last class which is the Bivalvia. To begin with, in Echinodermata there are four classes that will be discuss and the first class will be Ophiuroidea. Ophiuroidea is a class of the phylum Echinodermata, which brittle star is a good example of it.
Important tapeworm parasites of humans Cestoda is a class of phylum platyhyelminthes. The best-known species of this class are called tapeworms. This is a class of parasitic flatworms, their life histories are vary but they mostly live in the digestive tracts or gut of humans and other vertebrates as adult, and sometimes they are present in the bodies of animals as juveniles. All cestodes contain atleast one and often more than one host. They lack digestive tract, mouth and senory organs, they have unique body extension called microtiches which help in absorption of host nutrients.
Besides these, when living in swamps or rivers, they will be also co-existing with shrimps and fishes. They are rarely alone, as they move in large groups, especially when laying eggs. They are also used as food for indigenous people, so at certain times, the conch will be in abundance but then gradually drop as they are caught and eaten. The average life span for Pomacea urceus is 2-4 years, with some living longer (Holswade 2013). Behavior: Pomacea urcues is an amphibious.
It is claimed that cuttlefish are the fastest color changers in the whole animal kingdom. Swimming: Cuttlefish use their fins that surround their body for swimming. When quick movement is needed, they can rapidly expel water and move quickly by jet-propulsion. The bony structure “cuttlebone” is used to regulate the animal buoyancy through changing the gas-to-liquid ratio in the chambered cuttlebone that may be filled with gas and/or water depending on the position of the cuttlefish in the water