How marine fish and inverts breed in the ocean. 

  

.                                      (Currents)  

The cycle of life is at the most concentrated throughout the tropical waters of the world, which is within close proximity to the equator, say, a thousand klms either side, in shallow waters.    

This area has a breeding cycle that is perpetual (, unlike most southern species that breed for the summer), this is the reason the pristine areas of our far north have so much life and so much to give to the entire east coast of Australia, in this example. 

Around the world the ocean currents vary, some run seasonally, some run constantly, some in surges.

Our east ausy current, runs most of the year with lager surges, which happens as the sun heads towards our side of the equator

We have four main surges sometimes called eties. They start towards the warmer months and ease off around the end of the warmer months, but are still part of the east ausy current.   

                                    (Breeding and dispersal)

The oceans cycle of life happens as a result of temperature, moon cycle, tides or currents. One or all of these set off instinctive switches within our ocean creatures compelling them to breed. Almost all the ocean’s inhabitants release eggs or sperm or larvae into the surrounding waters. Some intentionally carry out this action to moonlight, darkness or a specific current or condition.

 

All this is designed to give their offspring the best chance of survival. Once a creature releases their eggs, sperm, larvae etc. (or for some creatures, they have live young or hatch from eggs attached to a rocky surface) they are at the mercy of the ocean’s currents and surges. At this stage, most have a tiny bubble or use their swim bladder to keep them near the surface to be apart of and feed on the plankton. This process can go on for days or weeks as they grow and are carried along by our east Aussie current. From birth or release to the time that they are too big or leaving their transparent stage, they may be carried 20kms or they may travel 2 thousand klms, it depends on many things as to where they reach the stage where they need to head for the floor of the ocean or find any shelter, as predators may soon be able to see them. From this stage, the massive kill off begins. The tiny amount of reef areas compared to sandy bottoms, massive depths, estuaries and they are also washed up on beaches and eaten by filter feeders like whales, corals, anemones, clams etc, all these claim massive numbers. Also when carried too far south, the winter kills all tropical species. Then you combine predators as they grow, territorial fights and water quality changes, you are left with what we see, only one percent, that is what is left for us to affect.

 

A miniscule amount reach adult hood of countless billions produced in our seasonal tropics. This is unlike either side of the equator, where the oceans cycle of life is perpetual.

 

There are several ways that the different creatures produce offspring in the ocean, some give birth to live young, then a few mouth breed and pouch brood, and then there are some that lay eggs, then you have others that sense sperm or egg release as a signal to release. Then you have inverts like most anemones, tube worms, corals etc that divide and release eggs or sperm as well, this gives them more chances of perpetuating their species.

 

Over all, it is a very complex and tough beginning for all the creatures that make up the oceans cycle of life.

                                   (Southern breeding)

 In the cooler waters the breeding is seasonal as the young need the warmer temperatures to grow and attain some size for survival. The colours on average, of the cooler species is darker, more dull, as they do not need to blend in with tropical invert colours and other factors can affect them, like food types which are different in cooler waters.

 Most of the life that comes past in the stronger currents doesn’t make it to the shoreline reefs unless something happens to push them in.

 Once around 23 years ago and then again 16 years ago, we had mini cyclones come in close to Stradbroke Island then the gold coast, both times several angel fish species were predominant in the plankton, ready to drop, the very strong winds literally bent the current in towards shore.  

 In these years from late February on when the juveniles were big enough to see, we found enormous amounts of semicirculatus, imperators, bi colours, and coral beauties all in massive numbers.

 So the next time we have a big blow between September and November, expect a lot of aquarium species to saturate the coastline.

                                          (Eggs and sperm)

 Some species, for instance, like the damselfish, which includes clown fish, lay their fertilized eggs onto a hard surface to await birth.

 Shrimps and lobsters flip there tail when their young are developed enough, until they are all gone, then shed their shell releasing hormones to attract a male to do his bit before her shell goes hard, sometimes we find many males waiting for the big moment, some shrimp have a partner to do this. Angelfish, male and female do a little dance normally up off the bottom then, release eggs and sperm to make contact, most wrasse, school normally, releasing sperm and eggs to make contact, some species have partners.  Corals, feather stars and tubeworms release their eggs and sperm to find each other, although tubeworms will detect a release from the opposite sex for them to release as well.

  Most of the creatures in the ocean release the young or eggs to swim or float in to the plankton rich currents to be carried along until too big to be there, then the recently placed log, rock formation or sunken ship, that was void of life, gradually becomes abundant with the oceans cycle of life.