Euteleostei

OEB 130: BIOLOGY OF FISHES
Overview of teleost fish diversity
Outline
Lecture outline:
Very brief review of fish phylogeny:
sarcopterygians and early actinopterygians
The teleost fish clade (broad overview)
• What is a teleost fish?
• Major trends in teleost fish evolution
-- fin placement, scales, tail shape
-- maxilla and premaxilla
• Introduction to the major groups
-- Elopomorpha and Osteoglossomorpha
-- Otocephala – (much more in March 30 lecture)
-- Euteleostei
-- Salmons and relatives
-- Neoteleostei, viperfish, Scopelomorpha
-- Acanthomorpha: Beryciformes and Percomorpha
Exam next Monday
IMPT. exam notes:
1) First hour exam next Monday Feb. 29th.
2) The exam will last 50 minutes
3) Questions will be very short and short
answer
4) No multiple choice questions
5) Exam covers both the lectures and readings
6) Pay special attention to the drawings done
in class, with a focus on the phylogenies.
Practice drawing these for yourself, and
correlate the major groups with the readings
that you did
First exam
in one
week!
Vertebrate tree – Sarcopterygii (lobe-finned fishes)
~35,000 ray-finned fishes
~ 30,000 lobe-finned “fishes”
Major divergence
in vertebrate evolution
Ray-finned fish (Actinopterygii) phylogeny: broad overview
Actinopterygii
Holostei
Chondrichthyes
Polypterus
and relatives Chondrostei
Teleostei
† Cheirolepis
1. Single dorsal fin
2. Fin ray structure: lepidotrichia
3. Scale structure
Actinopterygii = ray-fin
Teleost fish phylogeny: broad overview
Otocephala
Elopomorpha
(tarpons and eels)
Clupeiformes
Ostariophysi
Osteoglossomorpha
(“bony tongues”)
Euteleostei
Teleostei
1. Mobile premaxilla bone in the skull
2. Specialized tail bones
3. Median basibranchial tooth plates
What is a teleost fish?
Selected key shared derived characters
(synapomorphies)
Teleostei:
1) Mobile premaxilla bone in head
2) Elongate bones in the tail skeleton – uroneurals
(yellow in diagram below)
3) Median basibranchial tooth plates
2
1
Remember the premaxilla with the ascending process
neurocranium
Ascending
process
eye
operculum
Pectoral
girdle
suspensorium
Premaxilla
maxilla
mandible
Jaw joint
hyoid
Pectoral
fin
Teleost character (1) Mobile premaxilla bone in head
Early actinopterygians
have a fixed premaxilla
and maxilla in the
upper jaw.
The maxilla is actually
fixed in place too.
Functional implications?
This is the head of a
paleoniscoid fish, an
early fossil actinopterygian.
Teleost character (1) Mobile premaxilla bone in head
Early actinopts: no mobile
bones in the upper jaw
Amia (the bowfin) has a mobile
maxilla (blue arrow)
Black area and
arrow shows joint
where movement
can occur.
Teleost fishes like Elops
(the ladyfish or ten-pounder)
has a both mobile maxilla and
premaxilla (blue arrows)
Teleost character (1) Mobile premaxilla bone in head
pmx
maxilla
Many changes in the
maxilla-premaxilla
relationship during teleost
evolution.
Important functional
implications here too!
Ascending process
(allows significant
jaw protrusion)
Teleost character (2): Elongate bones in the tail skeleton:
uroneurals
Teleost character (2): Elongate bones in the tail skeleton:
uroneurals
Caudal fin rays
uroneural
Modified last
caudal vertebra
Vertebra
Haemal spine
Hypural plate
(midline)
Teleost character (2): Elongate bones in the tail skeleton:
uroneurals
Amia calva
(bowfin) –
pre-teleost
Elongate uroneural
bones
Early (fossil)
teleost fish
tail skeleton
Functional implications
are unknown: stiffen
the upper lobe?
Teleost character (2): Elongate bones in the tail skeleton:
uroneurals
The teleost fish tail
Externally
symmetrical
tail …
But internally
asymmetrical
skeleton
Teleost character (2): some diversity of tail shapes
Non-teleost tails
Teleost tail
Teleost character (3): Median basibranchial tooth plates
Primitive actinop.
condition – small
toothplates scattered
among the ventral
gill arch elements
(as in bichirs, gar, etc)
Looking down from above
on the ventral gill arches,
to show the basibranchial
tooth plates.
Teleost condition –
midline
toothplates on the
ventral gill arch elements
Teleost fish phylogeny: broad overview
Otocephala
Elopomorpha
(tarpons and eels)
Clupeiformes
Ostariophysi
Osteoglossomorpha
(“bony tongues”)
Euteleostei
Teleostei
1. Mobile premaxilla bone in the skull
2. Specialized tail bones
3. Median basibranchial tooth plates
Actinopterygii = ray-fin
Some major trends in fish evolution:
fin positions
Pectoral
fin
Note change
in the relative
position of
these fins.
Pelvic
fin
Evolutionary patterns of fins – another view
pectoral fins
pelvic fins
dorsal fin(s)
anal fin
caudal fin
(spiny-finned fishes)
(“true” bony fishes)
(ray-finned fishes – 28,000 species)
Many unanswered questions:
•Effect of fin position?
•Effect of fin shape?
•Hydrodynamic
and mechanical
function?
(spiny-finned fishes)
(“true” bony fishes)
(ray-finned fishes – 28,000 species)
Some major trends in fish evolution:
scales
Thinner, lighter cycloid and ctenoid scales replace the heavy
dermal armor of primitive ray-finned fishes. Some fishes (e.g.
eels) lack scales.
Diagram is missing
the peg and socket
Fish scales
Teleost fish phylogeny: broad overview
Otocephala
Elopomorpha
(tarpons and eels)
Clupeiformes
Ostariophysi
Osteoglossomorpha
(“bony tongues”)
More detail
in a later slide
Euteleostei
Teleostei
1. Mobile premaxilla bone in the skull
2. Specialized tail bones
3. Median basibranchial tooth plates
Actinopterygii = ray-fin
Elopomorpha (Eels, tarpons)
Eels and tarpons and relatives
have leptocephalus larvae
(leaf-head)
• Eels are the best known members with an amazing life history
• Include moray eels, conger eels, deep sea “spiny eels” and
gulper eels
• Bonefishes, tarpon, tenpounders (ladyfishes) – good fishing!
• 24 families, around 860 species
• United by the presence of a leptocephalus larva
Elopomorpha (Eels, tarpons)
A moray eel: recall the raptorial pharyngeal jaws
Elopomorpha (Eels, tarpons)
tarpon/ladyfish
Elopomorpha (Eels, tarpons)
The leptocephalus larva,
a synapomorphy for
elopomorph fishes
Leptocephalus = “leaf head”
Elopomorpha (Eels, tarpons)
Metamorphosis of an eel larva
Elopomorpha (Eels, tarpons)
Movie of locomotion in a leptocephalus
Elopomorpha (Eels, tarpons)
Movie of locomotion in a leptocephalus
Swimming of a leptocephalus larva
Elopomorpha (Eels, tarpons)
Freshwater eels are catadromous, they enter the ocean as adults, migrate
to a spawning area in the Sargasso sea,
where they spawn & then die. Live most of their lives in fresh water.
Sargasso sea
Elopomorpha (Eels, tarpons)
Freshwater eels are catadromous, they enter the
ocean as adults, migrate to a spawning area
where they spawn & then die.
Teleostei: Osteoglossomorpha
(bonytongues)
•
•
•
•
4 families, around 220 species.
Often exhibit parental care of young
Clown knifefish, mooneye, arowanas, butterfly fish
Elephant fishes (Mormyridae): 201 species, freshwater,
African, and these fishes can both generate and detect
weak electric fields for communication and prey location
Osteoglossomorpha (bonytongues)
arowana
Elephant fish
African knifefish
Osteoglossomorpha (bonytongues)
Separate lecture
on the Otocephala
clade coming on
March 30.
Otocephala
2 major groups
Clupeomorpha
364 species
herrings, anchovies,
menhaden, etc.
Abundant ocean
schooling fishes
of great commercial
importance.
Ear-swimbladder anatomy
Caudal skeleton anatomy
Ostariophysi
8,000 species
28% of all fishes
68% of freshwater fishes;
carps, milkfishes,
characins, zebrafish,
goldfish, many popular
aquarium species,
catfishes, and gymnotids –
South American
knifefishes
Otocephala: Clupeomorph clade
Otocephala: Ostariophysi clade
Much more in
the March 30 lecture.
Teleost fish phylogeny: broad overview
Otocephala
Elopomorpha
(tarpons and eels)
Clupeiformes
Ostariophysi
Osteoglossomorpha
(“bony tongues”)
Euteleostei
Teleostei
More detail
next slide
1. Mobile premaxilla bone in the skull
2. Specialized tail bones
3. Median basibranchial tooth plates
Actinopterygii = ray-fin
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Percomorpha
Protacanthopterygii
Acanthomorpha
(~17,000 species)
Otocephala
(~9,000 sp)
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost
Euteleost fishes (the Euteleostei)
•
•
•
•
Tremendous species diversity
Characters defining the clade less than solid
Around 20,000 species
346 families
Figure 24.15
Selected key shared derived characters
for Euteleostei
Euteleostei:
1) Dorsal adipose fin – lost in many later clades **
2) Nuptial tubercles on head and body – lost in many clades **
3) Unique anatomy of the uroneural bones and other
1
skeletal elements
2
1
** traditional characters but pretty lame;
molecular analyses support this grouping too
One fairly good character for Euteleostei
3
Bone stained red,
cartilage blue
Euteleost character 3 – midline caudal skeleton cartilage
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Percomorpha
Protacanthopterygii
Acanthomorpha
Otocephala
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost
Protacanthopterygii
argentiniform (202 species) and
salmoniform (154 species) fishes
• Not a very well-defined group and some controversy over the
included species and higher taxa.
• Includes the esocids – pikes and mudminnows
• Trout and salmon, and walleye
• Argentinoid fishes, smelts, and some other
odd deep-sea fishes
• 12 families, 366 species
Protacanthopterygii
Freshwater pike
mudminnow
Trout and salmon
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Percomorpha
Protacanthopterygii
Acanthomorpha
Otocephala
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost
The Neoteleostei
major defining character is the retractor dorsalis muscle
Remember the
UPJ!
1
2 3
4
5
Premaxilla
Lower jaw
Basihyal
(“tongue”)
Hyoid
Urohyal – part of the hyoid
embedded in the sternohyoideus muscle
Pectoral
girdle
The Neoteleostei
major defining character is the retractor dorsalis muscle
Remember the
retractor dorsalis muscle
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Percomorpha
Protacanthopterygii
Acanthomorpha
Otocephala
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost
Viperfish (Stenopterygii)
• Mostly deep-sea fishes: meso- and bathypelagic
• 391 species: hatchetfishes, bristlemouths
• Families of note include the Stomiidae (stomiiform fishes -dragonfishes)
• Photophores, barbels, big teeth!, dark color
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Percomorpha
Protacanthopterygii
Acanthomorpha
Otocephala
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost
Scopelomorpha
(lanternfishes / myctophiform fishes)
•
•
•
•
•
2 families, around 250 species.
Lanternfishes / myctophiform fishes
Highly abundant group of mesopelagic fishes in the oceans
Often diurnal migration from surface to 2000 m
presence of non-bacterial luminescent organs (forming the lanterns
of these so-called lanternfishes).
• myctophid light organs are photophores and are species specific
Scopelomorpha
(lanternfishes)
•
•
•
•
•
2 families, around 250 species.
Lanternfishes / myctophiform fishes
Highly abundant group of mesopelagic fishes in the oceans
Often diurnal migration from surface to 2000 m
presence of non-bacterial luminescent organs (forming the lanterns
of these so-called lanternfishes).
• myctophid light organs are photophores and are species specific
The Euteleostei – more detailed branching
Scopelomorpha
(Lanternfish)
Gadiformes (cods)
+ zeiformes
Beryciformes
Smelts
viperfish
Protacanthopterygii
Percomorpha
Acanthomorpha
Future lectures on
the Acanthomorpha
Otocephala
Neoteleost fishes: 1 trait
Euteleostei: ~ 3 traits
Euteleost = “true” teleost