Can African cichlids change gender?

Why do some cichlids have egg spots?

This unique adaptation, present in East African haplochromine cichlids, is thought to represent male quality and may assist cichlids to attract a female, according to Oklahoma State University. Males lacking egg spots are often the target of interspecies aggression from other males.

How many types of cichlids are there in a freshwater aquarium?

12 Colorful Cichlid Types for your Freshwater Aquarium. Cichlids comprise the largest family of freshwater fish and their diverse representation at The Ocean Floor is no exception. A little more than half of our selling tanks and most of our display aquariums are allocated to cichlids.

Do color and pigmentation patterns matter in East African cichlids?

Color and pigmentation patterns seem to play a central role in the explosively radiating cichlid fish species in the East African Great Lakes in general, and in the haplochromine cichlids in particular, , , . Haplochromines contain the vast majority of East African cichlid species with the entire species flocks of lakes Victoria.

What are egg dummies in cichlids?

Egg spots or egg dummies are round or oval-shaped markings found on the anal fins in males of approximately 1500 haplochromine cichlid species. The markings consist of a conspicuous yellow, orange, or reddish inner circle and a transparent outer ring.

Why do female cichlids have egg spots?

Bernd Egger and coauthors report in a recent issue of the online journal PLoS ONE that female haplochromine cichlids exhibit a pre-existing sensory bias for egg-shaped structures and egg coloration (red, yellow and orange), which may have been enough to trigger the evolution of egg spots in the anal fins of the male fish.

How do fish eggs get fertilized?

The male then presents the egg-spots on the anal fin; the female seemingly nuzzles at these egg-spots and the male releases sperm so that the eggs are fertilized within the females’ mouth. The eggs and larvae then stay in the buccal cavity of the female for a period of several days to a few weeks.

Where do freshwater cichlids come from?

For the most part, cichlids come from freshwater sources in mainland Africa and tropical America – which makes this guide to caring for freshwater fish a good place to start. After establishing the basics, there are a few general rules of thumb to keep in mind when creating a tank for freshwater cichlids.

What are the egg spots on the male fin for?

The male’s black anal fin has yellow “egg spots” on it that are used in mating. When a male is ready to mate, he seduces a female with a shuddering dance, causing her to lay an egg on the bottom in response.

Does multiple paternity exist in lekking cichlid fishes from Lake Malawi?

45. Kellogg KA, Markert JA, Stauffer JR, Kocher TD (1995) Microsatellite variation demonstrates multiple paternity in lekking cichlid fishes from Lake Malawi, Africa. Proc R Soc Lond B 260: 79–84.

Which fish has egg-spots on its anal fin?

(A) A male of A. burtoni showing egg-spots on its anal fin. (B) Natural variation of egg-spots in A. burtoni. All these fish were caught and photographed at the south-eastern part of Lake Tanganyika in Zambia.

Why don’t fish lay eggs anymore?

Once she releases these eggs into the water, they’re much harder to collect, clean, and package. Second, there’s no market for ovulated or fertilized fish eggs. When the female begins to spawn, the exterior of her eggs deteriorates to allow for the penetration of sperm.

Are cichlids marine or freshwater fish?

They are categorized as “secondary freshwater fish” – meaning their ancestors were marine fish. It is believed that cichlids moved to freshwaters from the marine environment, and they have features relating to a number of marine species including the damsels, wrasses, parrot fish, and surfperches.

What are the egg-shaped markings on the anal fin called?

In many species, the male will display egg-shaped markings on the anal fin known as egg spots. Some males have a bump on the head, referred to as a nuchal hump.

Do male cichlids have egg spots on their anal fin?

I have several juvenile cichlids with egg spots on their anal fin and I was wondering if I can tell if they are male without looking at their vents? Nope, females also have egg spots. I agree with him! Nope, females also have egg spots.

Do female fish lay eggs in front of the male?

In our female two-way choice experiments two size-matched males were presented to a focal female in two outer tanks arranged on both sides of the central female tank (Figure 2A). In experiment 1. 1, 7 females laid more eggs in front of the male with many egg-spots and 11 females laid more eggs in front of the male with fewer egg-spots.

What eats cichlid eggs?

Certain species of synodontis catfish will try to eat the cichlid’s eggs while the couple is breeding. These predators will have their attention diverted to the egg spots and will give the parents a fighting chance. In certain species, only the male will have egg spots.

What do we know about the history of Malawi’s cichlid fishes?

The cichlid fishes of Lake Malawi are famously diverse. However, phylogenetic and population genetic studies of their history have been difficult because of the great amount of genetic variation that is shared between species.

Why do closely related Cichlids share genetic variation?

The extensive sharing of genetic variation by closely related cichlid species has traditionally been attributed to the simple persistence of variation that was present in ancestral species (Albertson et al., 1999; Moran and Kornfield, 1993; Parker and Kornfield, 1997).

Is Lake Tanganyika an evolutionary reservoir for East African cichlid fishes?

Nishida, M. (1991) Lake Tanganyika as an evolutionary reservoir of old lineages of East African cichlid fishes: Inferences from allozyme data. Experientia 47, 974–979. Parker, A. & Kornfield, I. (1996) Polygynandry in Pseudotropheus zebra, a cichlid fish from Lake Malawi.

What is the bump on the male fish head called?

In many species, the male will display egg-shaped markings on the anal fin known as egg spots. Some males have a bump on the head, referred to as a nuchal hump. Although females can also develop a nuchal hump when spawning, it is never as prominent as that of the male.