AHMAD ALI, SEAFDEC

Biology of sharks and rays

AHMAD ALI, SEAFDEC

Liver

Internal organs of Mustelus lenticulatus

Spiral intestine

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Liver (deep water shark: rich with oil)

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Reproductive modes of shark1. Oviparous:Producing eggs that hatch after being ejected from the body of female parent2. ViviparousProducing live young from within the body of the parent femaleOvoviviporous:Producing eggs that hatch inside the uterus then give birth to the young (whale shark)

1. Shark Bony fish

Internal fertilization External fertilization

Small number of egg Larger number of egg

Big size of egg Egg with small amount of stored yolk

Produce large young that are hatch, or are born

Many stage before complete of their development (Note: Some bony fish also produce live young eg: guppy

Survival rate of young very high Highly vulnerable to predator sor nature

………………………………………… …………………………………………….

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

What is this?

AHMAD ALI, SEAFDEC

Scar on female body (love bite before mating)

AHMAD ALI, SEAFDEC

Mating bite

AHMAD ALI, SEAFDEC

Mating scar

AHMAD ALI, SEAFDEC

Internal fertilization

clasper

cloaca

Clasper(modified portions of the pelvic fins in male sharks, rays and chimaeras used for transferring sperm to the female

Cloaca(a common opening for digestive, urinary, and reproductive tracts in many fishes)

AHMAD ALI, SEAFDEC

Claspers

Mode of Reproduction

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Viviparity (Live-bearing sharks)

Pregnant female of Centrophorus

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Bull shark

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Carcharhinus sealei (2 pups)

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Hemigaleus microstoma(Weasel shark)

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Whale shark; 350 pups

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Oviparous

AHMAD ALI, SEAFDEC

Egg cases of oviparous shark

Photo credit : Dr. Keiichi Sato

Okinawa Churaumi Aquarium, Japan

Swellshark

Zebra shark

bambooshark

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

The egg case generally has tendrils and stickyfilaments that aide in attaching the egg to somesort of substrate where the eggs incubate.

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Smoothnose wedgefish.

Mode of Reproduction (Rays)

Viviparous: Producing live young from within the body of the parent female

AHMAD ALI, SEAFDEC

Pastinachus solocirostris

AHMAD ALI, SEAFDEC

Neotygon kuhlii

AHMAD ALI, SEAFDEC

Gymnura japonica

5 youngs

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

Rhina encylostoma

AHMAD ALI, SEAFDEC

• Liver: Sharks have large livers that are particularly rich in oil. It is thought that this oil provides the animals with buoyancy, and helps to prevent them from sinking when they are stationary. Sharks which do not have air bladders are heavier than water.

• Air bladder. Many bony fishes have air bladder in their body cavity. By adjusting the amount of gas it contains they are able to make their bodies weightless in the water.

Other Information:

AHMAD ALI, SEAFDEC

Liver

Carcharhinus lucas

AHMAD ALI, SEAFDEC

Heart (very small compare with TL)

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

AHMAD ALI, SEAFDEC

• Intestines: Sharks have short, compact intestines which take the basic form of a spiral staircase arrange within a cylinder. This spiral valve-as it is known-varies in form from species to species

• Bony fishes intestines vary in length according to the type of food that is eaten. Meat eaters generally have short intestines, and plant eaters long ones, sometimes elaborately folded

AHMAD ALI, SEAFDEC

Spiral valve: Alopias supersiliosus