1. Labroidei
Omar Sinno
Michelle Harris

2. Labroidei Class: Actinopterygii Order: Perciformes Suborder: Labroidei
4 Families within Suborder Labroidei
Cichlidae
Embiotocidae
Pomacentridae
Labridae
Includes the scarid and odacids, although many argue that they are separate families

3. Labroidei
Suborder includes extremely speciose and widely inhabited species.
Tropical and Temperate marines species
Reefs, kelp beds, surf zones and tide pools
Tropical with few temperate freshwater species
Lakes, sluggish rivers and fast streams
Few species found in brackish water

4. Pharyngeal Jaw : Uniting the Labroidei
Fused fifth ceratobranchials with teeth
Muscle “sling” suspending the lower pharyngeal jaw from the skull
Articulation between the upper pharyngeal jaws and the base of the skull without intervening muscle
Undivided sheet of sphincter esophagi muscle
Diversification of jaw structures integral to diet choice and speciation of cichlids.

5. Family Cichlidae
Generally tropical freshwater, however few found in brackish waters.
Nearly all species endemic to African rift Lakes.
Other endemic species found in North America, South America and the Middle East.
However, introductions have made them worldwide.

6. Family Cichlidae
Non-continuous lateral line and single nostril on each side.
Average inches in length but some species up to a meter long.
Several different body shapes:
Stream-lined
Disc
Tubular

7. Family Cichlidae
Diversification of mouth, jaw and teeth allow cichlids to eat a wide variety of food.
Mollusks, algae, insects, zooplankton, other fish, detris, plants and scales.
Predation styles include both ambush and open-pursuit.
Caprichromis rams head of mouth-brooding females, making her spit out eggs. Caprichromis then eats the fry.
Nimbochrmois and Parachromis play dead to lure in small fish.

8. Family Cichlidae Very Territorial- Levels of territoriality is diverse
Feeding (one of few f.w. spp) or Mating territoriality
Can communicate
Visual- color change may signify aggression, dominance, individuality
Tactile- “mouth fighting”
Chemical- distinguishing fry
Acoustic

9. Family Cichlidae Invasive Cichlids
Cichlids have been introduced by aquaria trade
1300 aquarium species!
California – Rio Grande Cichlid
Hawaii – Jewel Cichlid
Florida – Mayan Cichlid
Australia – Pearl Cichlid
Game Fishing
Peacock Bass
Biocontrol
Food
Egypt: Delicious Tilapia
Uganda: Nile Perch

10. Cichlidae: Breeding Methods of mating diverse as well
Monogamy
Courtship rituals and parental care common
Polygynous
Male or female territoriality
Polygynandrous
“Lekking” (“To play” in Swedish)
Congregation of 5,000-50,000 males
Males build nests inshore or in open waters
Females come to lay eggs in nests
Extended Family model
Colonization of related individuals with dominant male

11. Cichlinds displaying Lekking

12. Family Cichlidae Two models of Reproduction Mouth-Brooding
Most polygynous, monogamous and sexually dimorphic
Females and Males may mouth-brood
Substrate-Brooding
Fertilized eggs adhered to substrate and guarded by parents until hatched.
Parents tend to be monogamous or sexually monomorphic.

13. Sensory Systems and Speciation
Cichlid coloration and vision supports that geographic isolation not necessary for speciation in Cichlids.
Mutations and adaptations in vision allows different cichlid species to inhabit different levels in the water column.
Fish have adapted to best respond to certain colors that correspond to differences in color in varying depths.

14. Conservation of Cichlidae
43 species extinct
Small habitats in endemic locations make native species vulnerable to extinctions
Introduction of Nile Perch to Lake Victoria as food source has decimated cichlid populations.

15. Cichlids-Speciation
There are a number of hypotheses as to why the cichlids are so diverse
Lake Victoria flowed over into smaller surrounding lakes allowing the cichlids to inhabit the smaller lakes. When the water recedes, the fish in the smaller lakes are isolated from the rest of the population leading to speciation. When Lake Victoria floods again, some of the fish swim back from the small lake into Lake Victoria.
Other hypotheses theorize that sympatric processes within the lake caused divergence

16. Cichlids-Speciation
So there is a large number of species, but how fast did they diverge?
There are 900 species in African rift lakes. 12,400 years ago, Lake Victoria was a marsh. This would indicate an extremely fast pace for speciation
However, molecular clock data calculated using an assumed 5.6 percent divergence in DNA sequence every million years came up with the conclusion that Lake Victoria cichlids began evolving 100,000 to 200,000 years ago. This indicates that cichlids diverged after the break up of Gondwanaland.
This is supported by the number of cichlids in South America. They migrated between Africa & South America when the two were connected as Gondwanaland.

17. Cichlid Sympatric Speciation

18. Embiotocidae Surfperches
Inhabit marine waters, typically kelp beds, rocky reefs, and tidal zones
Some species eat zooplankton, while others eat invertebrates
The only family of vivparous in Labroidei

19. Pomacentridae
Includes damselfish and clownfish

20. Damselfish
Resides in tropical marine waters, typically in shallow areas close to coral reefs
Highly territorial
Guard a small patch of algae in a symbiotic relationship
The damselfish tend their algae like a garden
They strategically feed on certain areas so as not to deplete the algae
Viciously attack any fish trying to steal a bite
Males court females from their patch.
If successful, they also guard the eggs

21. Clownfish http://www.youtube.com/watch?v=bZ1KDf3O-qU
Live in anemones in tropical marine waters
Why don’t the anemones sting the clownfish and inject them with neurotoxins?
The clownfish have a sugar based mucous rather than protein so the anemone does not recognize it as food
Their coevolution has led to the clownfish’s immunity to the neurotoxin

22. Clownfish Again this is a symbiotic relationship
The anemone protects the clownfish from predators
The clownfish eats matter off the anemone that could potentially be harmful
The clownfish also provide nutrients for the anemone through their fecal matter
Clownfish are monogamous in the Christian sense, til death do they part
Clownfish groups are typically comprised of a breeding pair and some pre-pubescent males
When the female dies, the dominant male becomes the female (protandrous hermaphrodites)

23. Labridae The wrasses Includes at least 500 species
Inhabit shallow, tropical marine waters, typically close to coral reefs but can range to colder waters
Wrasses are colorful and sexually dimorphic
Originally born as a mix of females and males
The dominant males and females become the breeding males (protogynous hermaphrodites)
The submissive males become female mimics, but do not become females
The submissive females remain females

24. Labridae
Some species also participate in a symbiotic relationship: the famed cleaner fish
Other fish swim to a group of wrasses and usually give a signal: open their mouth or orient themselves vertically
The wrasses come and clean the parasites off of the fish
The wrasses even make house calls to shy fish
Occasionally there are cheater wrasses who eat protective mucous or healthy tissue
The “clientele” fish rarely eat the wrasses due to the enormous benefit of being cleaned of all of their potentially deadly parasites

25. Odacidae This family includes a mere 12 species
Their habitat is the coastal waters off Australia and New Zealand
Body is long and slender like the wrasse
Teeth are fused together like in the parrotfish

26. Scaridae
Parrotfish
Inhabit shallow, tropical marine waters, typically around coral reefs
Typically one male has a harem of females
When the male dies, the dominant female becomes the male (again, protogynous hermaphrodites)
Produce pelagic eggs (buoyant eggs, if you forgot)

27. Scaridae
So aptly named because of their fused to teeth which look like a bird’s beak
They feed on algal fronds and pieces of dead coral
How do they eat coral, you ask
Massive pharyngeal teeth that grinds up the dead coral
They eat algal particles and live coral polyps
Fun Fact! The sand that you laid on while you tanned in the Caribbean is parrotfish fecal matter

28. Conservation
The main source of endangerment for these species is the depletion of the coral reefs
There are many factors
Global warming
Coral bleaching
Coral acidification due to high CO2
Coral disease
Coral mining
Pollution

29. Review questions
What is the main hypothesis for Cichlid speciation and what is the reasoning behind the accepted molecular clock?
What are the benefits that clownfish and anemone receive from their symbiotic relationship?
Which families are protogynous hermaphrodites and which are protandrous hermaphrodites
Think, what are some specific advantages to the damselfish gardening algae?
What is “Lekking”?
Why has the Nile Perch been introduced to the Lake Victoria region and what effect does it have to native cichlid species?
What are the advantages and disadvantages to the two types of brooding.
What types of water bodies would you think tubular, disc and stream-lined cichlids inhabit?