What is the meaning of external development?
External growth (also known as inorganic growth) refers to growth of a company that results from using external resources and capabilities rather than from internal business activities. The main advantage of external growth over internal growth is that the former provides a faster way to expand the business.
What animals go through external development?
Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce.
Which is better internal or external fertilization?
Internal fertilization has the advantage of protecting the fertilized egg from dehydration on land. The embryo is isolated within the female, which limits predation on the young. Fewer offspring are produced through this method, but their survival rate is higher than that for external fertilization.
Are humans internal or external fertilization?
Sexual reproduction starts with the combination of a sperm and an egg in a process called fertilization. This can occur either inside (internal fertilization) or outside ( external fertilization) the body of the female. Humans provide an example of the former whereas seahorse reproduction is an example of the latter.
Do fish offspring usually develop inside or outside the mother?
Since most fish species undergo external fertilization, it only makes sense that, for the vast majority of fish species (>95%), the eggs develop outside of the mother’s body. This mode of development is called oviparity and is used by many species that undergo internal fertilization as well.
How quickly do fish reproduce?
Males chase females, prompting them to release their eggs by bumping and nudging them. As the female goldfish spawns her eggs, the male goldfish stays close behind fertilizing them. Their eggs are adhesive and attach to aquatic vegetation. The eggs hatch within 48 to 72 hours.
How can we identify male and female fish?
Males are often slimmer but larger-bodied than females and are more vibrantly colored. The dorsal and anal fins of the male are more pointed, larger and more flowing than in the female. In many species, the male will display egg-shaped markings on the anal fin known as egg spots.
What helps fish breathe?
Fish breathe with their gills, and they need a constant supply of oxygen. Gills sit under the operculum. This is called the gill slit.
Do fish get bored?
But whether fish actually feel bored in a way we can relate to is harder to work out. This could be the aquatic equivalent of the pacing of a captive tiger that’s bored from a lack of stimulation. But the fish could also be stressed from an overcrowded or unfamiliar tank.
Do fish get thirsty funny answer?
Very interesting question. The answer is No. They don’t ever get thirsty. Marine fish are what’s called hypertonic to the seawater.
Do fishes feel pain?
“Fish do feel pain. It’s likely different from what humans feel, but it is still a kind of pain.” At the anatomical level, fish have neurons known as nociceptors, which detect potential harm, such as high temperatures, intense pressure, and caustic chemicals.
Do fishes feel lonely?
No, fish don’t really get lonely. Unlike humans, these animals don’t have very strong emotions or feelings. However, whether your fish will be happy alone or not depends on the breed. Some fish can get stressed if kept alone for too long, and stressed fish die very quickly.
Do fish talk to each other?
Fish are believed to communicate with each other for different reasons, including attracting mates, scaring off predators or orienting themselves. The gurnard species has a wide vocal repertoire and keeps up a constant chatter, Ghazali found after studying different species of fish placed into tanks.
Can fish understand humans?
Not only is a fish able to recognize a human face, complete with two eyes, a nose, and a mouth, but an archerfish is able to recognize a specific human face, able to detect and pick up the various details and nuances that make each individual appearance unique.
Do fish communicate with humans?
Most of the fish communicate with sounds. Many studies have recorded mainly 3 types of vocalizations: the croak, the purr and some popping sounds. Most of those sounds are not audible by humans due to their much higher frequency and can only be picked up by underwater microphones.
How do fish recognize each other?
Researchers have found that fish recognize each other and gather information by eavesdropping. They’re capable of remembering past social interactions that they’ve had with other fish, and they show affection by rubbing against each other. Dr.