The link is from a book called "A Field Guide to Anemone Fishes and Their Host Sea Anemones" by Daphne G Fautin and Gerald R Allen.
Published by the Western Australian Museum in 1992
This is a quote from the book and includes Larval Life and Social Structure.
LARVAL LIFE AND SETTLEMENT
Hatching generally occurs during the evening, shortly after dark on the sixth or seventh day after the eggs are laid. In an aquarium, the freshly hatched fish first sink to the bottom, but within a few minutes, swim to the upper part of the tank. The larvae are about 3-4 mm total length and transparent except for a few scattered pigmented spots, the eye, and the yolk sac. Recent studies of larval duration in damselfishes have greatly improved knowledge of early life history stages. By counting the daily growth rings in the ear bones (otoliths) with an electron microscope, scientists can determine the time between hatching and transformation to the juvenile stage. There is much variation between species of damselfishes, with the longest larval stages about 6-8 weeks. Clownfishes have the shortest larval period of damsels, ranging from about 8 to 12 days. It is assumed that during this time they are planktonic -- living in the surface waters of the ocean, where they are passively transported by currents. The short larval stage of anemonefishes is no doubt responsible for the localised distribution of many species.
The larval stage terminates when a young fish settles to the sea bottom and begins to assume the juvenile colour pattern. Aquarium observations indicate this metamorphosis is a rapid process, occurring within a day or so. At this stage it is vital for the young Amphiprion or Premnas to find a suitable anemone host or it will surely be consumed by one of its many predators. There is evidence that fish of some species can actively search and follow a trail of chemicals released by a host anemone, but others seem not to do that, and may locate a suitable host by sight, or simply encounter one by chance. For fish of some species, it takes several hours to become fully acclimated to the anemone once it is located; this is achieved by a series of progressively longer contacts with the tentacles, like the elaborate "acclimation behaviour" seen when an adult fish is artificially removed from its host. Other fishes seem capable of swimming right in without harm, according to Miyagawa (see chapter 5). Although she denied they go through "acclimation behaviour", she described swimming that resembles such behaviour. With 10 species of host actinians and 28 species of fish, there are probably many variations on how hosts are located and adapted to.
We assume that metamorphosis requires the presence of an anemone, since the fishes seem defenceless without one. We and others have done experiments proving that even adult anemonefishes cannot survive for long without the protection of a host actinian. What is obvious is that there are far fewer open slots available in appropriate anemones than there are fish to fill them. So there must be tremendous mortality among fry and larvae.
Even if it successfully locates an anemone, the immediate survival of the fish is not guaranteed. If the host is already occupied by anemonefish, the unusual social structure of the inhabitants makes life difficult for a newcomer. The number of fish that occupy a single anemone depends on species of fish, size of host, and sometimes size of the fish as well, but typically there is an adult pair and two to four smaller fish. As will be explained more fully below, the largest fish is usually the female and the next largest individual is her mate. A hierarchy, or "peck-order", exists in which the female is the dominant individual. There is generally an amicable relationship between the adult pair, and aggressiveness by the female is largely channeled into ritualised, non-harmful displays. Aggression is more overt farther down the hierarchy. The male spends considerable time chasing and "bullying" the next largest individual, which in turn vents its aggression on the smaller fish. Therefore, a new arrival becomes the immediate target for the resident fish. Attacks may be so severe as to drive away the newcomer, who must find another anemone or perish.
SOCIAL STRUCTURE AND SEX REVERSAL
The phenomenon of sex reversal is an intriguing component of anemonefish life history, the details of which have been discovered only in the past decade. Sex change occurs in many fishes. For example, it is now well established that most wrasses (Labridae) and parrotfishes (Scaridae) begin adult life as females and later assume the more colourful male phase. Similar changes are widespread among gropers (Serranidae), particularly in the subfamily Anthiinae, commonly known as fairy basslets. Therefore, it was not surprising to discover that this phenomenon extends to some pomacentrids as well. However, the unusual aspect of sex reversal in clownfishes is that the change is from male to female (protandrous hermaphroditism; the more common sort is protogynous hermaphroditism). As mentioned above, the largest and socially dominant fish in a particular anemone (or cluster of anemones in the case of Entacmaea quadricolor) is generally the female, whose gonads are functioning ovaries with remnants of degenerate testicular tissue. The smaller male, which in species such as A. frenatus and P. biaculeatus may be less than half the size of the female, has gonads that are functioning testes but also possess non-functioning or latent ovarian cells. If the dominant female dies or is experimentally removed, the male's gonads cease to function as testes and the egg producing cells become active. Simultaneously, the largest of the non-breeding individuals becomes the functioning male. This adaptation allows continuous reproduction; without it, an adult would have to await the arrival of a fish of the appropriate sex (which it would be only 50% of the time), thereby losing valuable breeding time, or it would have to seek out a mate, leaving its anemone and thereby risking predation both on itself and on its symbiont.
There is no difference in colouration between sexes in most anemonefishes, but there are exceptions. The sex-related colour difference is not always present in A. clarkii. In addition, slight differences may occur between sexes of A. perideraion and A. akallopisos. Males of both species often have orange margins on the soft dorsal and caudal fins. In P. biaculeatus, colour differences may be related more to size than to sex per se.