learn about as many fish as possible
learn and memorize their scientific names, then those of every other member in their genus
learn their basic care requirements, replicate these if you keep them
learn where they come from, understand what fish they naturally occur with
learn all of this about the fish they occur with
learn what their habitat looks like
learn what their dietary needs are, what they normally eat
learn their breeding habits, understand why they breed a certain way
learn and understand their behaviors, how and why they swim a certain way, why their fins are shaped a certain way, why their gills flare a certain way, why their bodies are shaped the way they are, why they have certain coloration, etc
let me use my knowledge on "cutter's blue eyed cichlid" as an example
cryptoheros cutteri, other members in the family include c.spilurus and c.chetumalensis
prefers pH of 7-7.6, hard water, little to no flow, water temp in the mid 70's up to high 80's. not very finicky with water quality, mine seemed almost indestructible.
they occur in guatemala and honduras, some other populations scattered in neighboring countries
naturally occurs with livebearing fish like those of the families gambusia, belonesox, brachyraphis, poecilia, alfaro, phallichthys, pseudoxiphophorus, and xiphophorus, as well as other cichlids like those of the thorichtys genus (and a whole array of other cichlids i won't go too much into detail of)
natural habitat is mostly rocky with a sand or silt bottom with gravel mixed in, occasional leaf litter or wood structure, sparse vegetation
naturally eats small invertebrates or soft plant matter
biparental breeding habits, both parents take care of the fry
usual convict type breeding behavior, pair digs a small pit in the sand, cleans off a flat surface nearby, lays eggs on said surface, raises fry until they are large enough to fend for themselves
not as "just add water to breed" as actual convicts are, some conditioning is needed, though they can spawn at a little over an inch and a half long. fry grow relatively slow.
i am not sure why they swim in the sort of darting motion they do, but i know that the streamers on the anal and dorsal fin of males is meant for sexual dimorphism and a sign that the fish is in good health and is strong enough to maintain good finnage (if i recall), spines are meant for defense to keep the fish from being swallowed easily by larger fish, the round tail is adapted to calmer waters where speed and being streamlined isn't necessary, though it still allows for enough water to be pushed in order to allow for quick bursts of speed. gill flaring is a territorial display, nothing special about it in cutteri especially. body is relatively tall, not necessarily streamlined but this also aids in keeping the fish from being swallowed by some predators. both sexes show barring, 7 bars that change in opacity based on the fish's mood, with one connecting the mouth to the eye. males have a yellow base color with a blue tinting around the peduncle and a brighter yellow stomach. (sexual dimorphism/to attract mates?) they also show dark red tinted fins. females have a mostly silver base layer and will sometimes have the same blue tinting as males. both sexes will show a breeding dress when spawning, where the entire base coloration of their bodies will lighten to a silver. i am not sure why breeding dresses are something they show but if i had to guess it's to act as some sort of warning to fish of the same species or others.
lifespan is around 7-10 years given proper care, possibly longer
made that a bit smaller so it doesn't take too much space up if noone wants to read it but my point is, while i know a good amount about the cutteri cichlid, or many other fish in general, i'm not an expert and i will not call myself an expert
because there is always more to learn, whether that be a result of you never hearing of certain information or new information being discovered about certain fish
regardless just enjoy the hobby, don't worry about working up any ranks and becoming an 'expert' in it
water doesn't boil if you watch it, as my dad says, so just don't pay too much attention to one thing and just learn more as you go, you'll reward yourself more that way
that's what makes this hobby fun and interesting
