Yellow labridens (Herichthys labridens) cichlids reproduce all year due to the constant conditions of the springs in the Rio Verde valley. In the rivers Verde and Santa María, I have observed most of the reproductive pairs from March to June, before the strong rains of the season arrive, starting late in May. Some minor breeding activity remains however as late as October. In the riverine habitat, pairs form before the establishment of territory. Territories are formed in shallow water at the base of a rock that serves as support for excavation of a cave. I have observed excavation carried out by both members of the pair, but apparently the female participates more actively. Defense of the territory in this phase of the reproductive cycle seems to be weak.
Once a cave is dug out that is big enough to fit the pair, spawning takes place. Eggs are placed on a vertical wall or the roof of the spawning cave. When a cave is not available, alternative surfaces are used for spawning. On two occasions I have observed the under side of a sunken water lily (Nymphaea sp.) leaf used for this end, simulating a cave. The eggs deposited by females are approximately between 300 and 1,000 in number, based on a couple of counts for average small females and an estimation of spawning size for more pairs, but reports of over 5,600 potential eggs in larger females are available (Diaz Pardo et al, 2002). Eggs are adhesive, ovoid, yellowish and around 2 millimeters in size in their major axis. In two days of close female care, which only leaves the spawn to the male for some minutes occasionally, the eggs hatch.
The fry are still unable to swim because of the weight of the heavy yolk sac with which they are born. They are placed on the bottom of the spawning cave or in a crack hidden among rocks or aquatic plants (if available). In this place they are cared for by the pair for about five days, which is the amount of time it takes them to consume the yolk under aquarium conditions.
When foraging, the fry are guarded by the pair for about five weeks. This is an estimate, as this is the approximate amount of time it takes them to reach 15 millimeters in length under aquarium conditions. This size is the biggest seen for fry with pairs in the wild. Fry care is unique and fascinating. The pair provides the fry with food, agitating the substrate, thus creating a cloud of detritus that releases floating edible particles. Both males and females create this cloud, frequently inserting their chests in the soft substrate and shaking their bodies and pectoral fins rapidly. Females are more often observed performing this behavior.
The female and fry stay close to the territory of the male, who chases away potential predators. The female stays close to the fry, as they move in a compact school, guided by their parents. The school’s direction is controlled by means of visual signs, consisting of spasmodic movements of the parents’ bodies, complemented by a quick opening and closing of their fins. During the night, or when danger approaches, the parents guide their fry to a protected place, which can be the spawning cave or, if it is no longer available, the thickness of aquatic vegetation.
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