3,895 answers about fish & aquatics
A healthy aquarium is a balanced one — water chemistry, filtration, stocking and feeding all work together, and most fish problems start with the water. This page gathers the fish and aquatics library of KinsLe Answers in one place, organized by topic for freshwater and saltwater keepers alike. Every answer is original, written by KinsLe, and tied to a real KinsLe feature.
297 answers in Young Pets — page 3 of 13
A young guppy that is failing to thrive falls visibly behind its siblings, staying tiny and grey while they grow and, in males, begin to colour. It hides in plant cover through feeding, holds its fins clamped, and may develop a slight bend to the spine or a hollow belly despite food being present. Because a healthy…
A young goldfish that is failing to thrive stops growing while its tankmates pull ahead, sits on the gravel or hangs near the surface instead of cruising, and loses interest in food it once rushed for. Clamped fins, a hollow belly behind a normal head, and wobbly, tilted swimming are stronger warnings in a fish that…
A young corydoras that is failing to thrive usually leaves its shoal to sit alone on the sand, stops nosing along the bottom for food, and looks paler and thinner than its tankmates. Shortened or reddened barbels, clamped fins, and rapid breathing at rest are further warnings in a fish that should be busy and social.…
A young bristlenose pleco is failing to thrive when its belly looks sunken instead of gently rounded, its driftwood shows no fresh rasp marks, and it stops producing the droppings a constantly grazing juvenile should leave overnight. Because this fish hides all day by nature, judge it at night: a pleco that no longer…
A young betta is failing to thrive when it loses its curiosity and appetite together — a juvenile that once rushed the glass now rests on the bottom or a leaf for hours, ignores food it used to strike at, and shows fading colour with fins held clamped. Stalled growth compared with its age, slow responses, and spending…
A young angelfish is failing to thrive when it stops growing alongside its siblings, hides behind the filter instead of competing at feeding, and holds its fins clamped rather than spread. Watch also for a body that looks pinched behind the head, long white stringy droppings, and a juvenile that hovers in one corner…
A young zebra danio can cope with no handling at all — its speed makes catching it a daily chase the whole school pays for. A juvenile danio netted or grabbed at risks a damaged tail, exhaustion from frantic darting, and a jump out of the tank, since danios launch themselves when cornered. Admire the school's energy…
A young pearl gourami can cope with no daily handling — it is a shy, slow fish whose long thread-like pelvic feelers are easily snapped by nets and fingers. A juvenile pearl startled by chasing retreats into plants, stops displaying its pearly spotting, and may skip the surface breathing and feeding that keep it…
A young kuhli loach can cope with no handling at all — it is one of the fish least suited to being touched. Its nearly scaleless, eel-like body is injured by nets and squeezing fingers, it burrows into substrate when frightened, and a juvenile dragged out of hiding for a daily check may stop emerging to feed at night.…
A young harlequin rasbora can cope with no daily handling — none is safe as a routine for a small schooling fish like this. A juvenile harlequin taken from its group, chased with a net, or lifted out of water loses the shoal security it depends on, dulls in colour, and may refuse food for the rest of the day. Watch…
A young guppy can cope with no direct handling at all — at fry and juvenile size it is simply too small and delicate for fingers or repeated netting. One chase around the tank can exhaust a young guppy, damage its developing tail, and trigger the hiding and feeding refusal that follow stress at this age. Let it grow…
A young goldfish should not be handled by hand on any day — the safe daily amount is none, even though goldfish look sturdy. A juvenile's slime coat rubs away on dry hands, its growing body is damaged by being lifted unsupported, and fancy varieties have especially delicate fins and eyes. Do tank work around the fish,…
A young corydoras copes with no daily handling — the safe amount is none, and even necessary moves need care. A juvenile cory's whisker-like barbels are easily damaged by rough nets and bare hands, its pectoral spines lock and tangle in mesh, and being separated from its shoal during a chase adds panic to the physical…
A young bristlenose pleco should have no daily hands-on handling at all — it is a nocturnal bottom-dweller built to hide, not to be held. Its cheek spines and stiff pectoral fins snag in nets, its bristles are delicate while they develop, and being dragged from its cave in daylight is a major stress event for a…
A young betta can cope with essentially no hands-on handling at all, and that is the safe daily amount. A juvenile betta's long, still-developing fins tear easily and its protective slime coat is stripped by dry fingers, while being chased or lifted out of water triggers a stress response its small body handles…
None as a daily activity: a young angelfish is a fish to watch, not to hold, and it copes with handling only as a rare necessity. Bare hands strip the protective slime coat and chill or stress the fish, and repeated netting damages its long fins and spooks it off food. When a move is genuinely unavoidable, herd it…
Compare your young zebra danios side by side once they are well grown, because sexing them is a comparison, not a single-fish test. Females are the larger, rounder fish, their bellies fuller and whiter, especially when carrying eggs, while males stay slim and torpedo-shaped and often show a golden yellow tint in the…
As your young pearl gourami matures, watch its throat and fins, because those are where the sexes part company. A male develops a rich orange-red flush across his throat and chest and grows longer, more pointed dorsal and anal fins, while a female stays paler and silvery at the throat, rounder through the body, with…
You almost certainly cannot sex a young kuhli loach, and experienced keepers will tell you the same. Kuhlis show no reliable external differences as youngsters, and even adults are usually only guessed at when a mature female grows thick through the body and, when full of eggs, shows a greenish tint through the skin…
With a young harlequin rasbora, compare the whole shoal rather than studying one fish, because the differences are matters of degree. Maturing males look slimmer and brighter, their copper colour richer and the black triangular wedge on the flank fuller, with its front edge curving down toward the belly. Females grow…
Guppies are one of the easiest fish to sex young, once you know where to look: the anal fin underneath the body. A young male's anal fin folds into a narrow, pointed rod called a gonopodium as he matures, and he stays smaller while his colours and tail pattern develop. A female keeps a triangular, fan-shaped anal fin,…
A young goldfish outside breeding season is genuinely hard to sex, because juveniles show almost none of the adult differences. When warmer water triggers breeding condition, a male develops small white tubercles on his gill covers and front fins and stays slimmer, while a female grows visibly rounder with a fuller…
Look down on your young corydoras from above, because that is the view where the sexes separate as they grow. A maturing female becomes noticeably broader and rounder through the body behind the head, while a male stays slimmer, smaller, and more streamlined on the same diet. Youngsters fresh from the shop are often…
Watch the bristles as your young bristlenose pleco grows, because that is where the answer develops. A maturing male grows a full set of fleshy bristles spreading up the middle of his face and around his mouth, while a female keeps only a short row along the edge of her lip, or almost none. Truly young plecos show…
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