How do shark reproduction differ from fish reproduction?

- Sharks:

- Internal fertilization: Male sharks insert their claspers into the female's cloaca to deliver sperm.

- Fish:

- External fertilization: Most fish species release eggs and sperm into the water, where fertilization occurs externally. Some fish engage in internal fertilization, but it's less common.

2. Embryo Development

- Sharks:

- Viviparity or Oviparity: Shark reproduction can vary depending on the species. Some sharks give birth to live young (viviparity), while others lay eggs (oviparity).

1. Viviparity: Developing embryos receive nourishment from the mother's body through a specialized structure called the placenta. The gestation period varies among species, ranging from several months to over a year.

2. Oviparity: Female sharks lay fertilized eggs enclosed in leathery or horny egg cases. The eggs develop and hatch outside the mother's body. Some species deposit the eggs in specific locations, while others release them freely into the water.

- Fish:

- Most fish species lay eggs that develop and hatch outside the parent's body. After fertilization, the eggs may be attached to surfaces, suspended in the water, or brooded by one of the parents (usually the female).

3. Parental Care

- Sharks:

- Minimal Parental Care: In most shark species, parental care is minimal or absent. After giving birth or laying eggs, the parents leave the young to fend for themselves.

- Fish:

- Variable Parental Care: Fish species exhibit a wide range of parental care strategies, from no involvement to elaborate care of the eggs and offspring. Some fish guard the eggs or fry, provide food and protection, or even carry the young in their mouths or pouches.

4. Reproduction Frequency

- Sharks:

- Low Reproductive Rate: Sharks generally have low reproductive rates. They produce relatively few offspring compared to many fish species, and the interval between reproductive cycles can be several years.

- Fish:

- High Reproductive Rate: Many fish species have high reproductive rates, producing numerous offspring multiple times during their reproductive season. This is often an adaptation to the high mortality rates of fish eggs and larvae.