Actinopterygian Relationships IV Biology of Fishes 10.11.12
Overview Presentation Topics Review (Actinopterygian Relationships III) Actinopterygian Relationships IV : Percomorpha
Actinopterygian Relationships
Actinopterygian Relationships
Actinopterygian Relationships Paracanthopterygii (cods, anglers, cavefishes, relatives) Acanthopterygii (spiny-finned fishes) - Mugilomorpha (mullets) - Atherinomorpha (silversides, flyingfishes, liverbearers and rel.) -Percomorpha (perch-shaped fishes)
Acanthopterygii
Actinopterygian Relationships Acanthopterygii (spiny-finned fishes) Most diverse group of bony fishes; ~15,000 species Two major synapomorphies Ascending process – dorsal extension of premaxilla Most highly developed pharyngeal dentition and function based on new muscle and bone attachments Ctenoid scales Physoclistous gas bladder 2 dorsal fins (1 spiny-rayed, 1 soft-rayed) Pelvic and anal fin spines Pelvic fins forward, pectoral fins laterally positioned
Acanthopterygii
Actinopterygian Relationships Acanthopterygii (spiny-finned fishes) Most advanced fishes, dominate shallow productive habitats of marine and many freshwater environments Controversial phylogeny (follow Nelson 2006)
Actinopterygian Relationships Paracanthopterygii (cods, anglers, cavefishes, relatives) Acanthopterygii (spiny-finned fishes) - Mugilomorpha (mullets) - Atherinomorpha (silversides, flyingfishes, liverbearers and rel.) -Percomorpha (perch-shaped fishes) pumpkinseed sunfish
Actinopterygian Relationships
Actinopterygian Relationships Percomorpha (“perch-shaped” fishes) Most advanced clade of fishes ~13,000 species; primarily marine, many successful freshwater Primary synapomorphy is anteriorly placed pelvic girdle attached to pectoral girdle directly or via ligament Pelvic fin with anterior spine and 5 soft rays (typically)
Percomorpha (basal groups) Stephanoberyciformes (whalefishes) Beryciformes (squirrelfishes) Zeiformes (dories) Gasterosteiformes (sticklebacks, seahorses) Synbranchiformes (swamp eels) Scorpaeniformes (scorpionfishes, sculpins, relatives)
Percomorpha
Percomorpha (basal groups) whalefishes dories squirrelfishes swamp eels seahorses, sticklebacks scorpionfishes, sculpins
Percomorpha Stephanoberyciformes (whalefishes) ~75 species Deepsea marine fishes Primitive percomorphs, more caudal fin rays (18-19) than other percomorphs (typically 17)
Percomorpha Beryciformes (squirrelfishes) ~144 species Nocturnal marine fishes Large eyes, head; also primitive caudal fin ray number (18- 19) Includes commercially important orange roughy (mature in 20-30 years, live past 150 years)
Percomorpha Zeiformes (dories) ~75 species Primitive marine percomorphs Protrusible mouths Not well-classified in percomorpha based on morphologies
Percomorpha Gasterosteiformes (sticklebacks, seashorses) ~280 species, primarily marine, small fishes Dermal armor plates, small mouths Sticklebacks very intensely studied (behavior, physiology, ecology, evolution) Unique reproductive behavior – “pregnant males”
Percomorpha Synbranchiformes (swamp eels) ~100 species Primarily freshwater, eel-like fishes Air-breathers Lack most fins, in some cases all fins Invasive species from pet trade
Percomorpha Scorpaeniformes (scorpionfishes, sculpins, relatives) ~1500 species, primarily marine fishes Phylogenetic placement in percomorpha debated Many lack scales, possess numerous spines Venomous lionfishes and stonefishes Freshwater sculpins Lumpfish (Cyclopterus) is most advanced
Percomorpha (advanced groups) Perciformes (perch-like fishes) Pleuronectiformes (flatfishes) Tetraodontiformes (puffers, triggerfishes, relatives)
Percomorpha
Percomorpha (advanced groups) Perciformes Pleuronectiformes Tetraodontiformes triggerfish yellow perch parrotfish flounders & halibuts ocean sunfish
Percomorpha Perciformes (perch-like fishes) Largest order of vertebrates – 160 families and over 10,000 species; more than 2/3 of all fishes Rapid evolution ~20 million years Marine (gobies, wrasses, seabasses) and freshwater success (cichlids, croakers, perches/darters) Some of the most recognizable fishes
Perciformes
Percomorpha Pleuronectiformes (flounders, halibuts, relatives) Asymmetrical morphology – both eyes on one side of head Teeth, scales, fins, pigmentation differ between sides Benthic, carnivorous, primarily marine; ~680 species Important food fishes
Percomorpha Tetraodontiformes (puffers, triggerfishes, relatives) “four teeth”; many lack true teeth (possess modified jaw bone) Most derived fishes, reduced bones, fins, morphology; ~360 species Trigger mechanism in trigger/filefishes Cartilaginous elements re-evolved (“come full circle”) tetraodotoxin