ZOO Chapter 7

Osteichthyes

Osteichthyes

“Bony fish”

feeding and respiration are functionally ________.

linked

Synapomorphies of osteichthyes

Endochondral bone, Lepidotrichia

Synapomorphies of Actinoptergyii

Single dorsal fin

Sarcopterygii

includes the lungfishes, coelacanths and all tetrapods

Sarcopterygii and Actinopterygii are ________.

sister groups

Derived trait of Actinoptergyii, with the exception of polypteriformes

Lung dorsal to gut

synapomorphy of neopterygii

mobile maxilla

Vertebrate Diversity and Evolution - _______ extant species, half of which are “fishes”

70,000

Teleostei includes ~______ species of fishes, compared to fewer than 50 in other clades.

30,000

There are only ______ species of gars and one species of bowfin, despite being abundant and important predators (and easy to see in Florida)

seven

Teleostei includes >___% of actinopterygians

>99%

3 Extant sarcopterygian fishes examples

coelacanth, Australian lungfish, African lungfish

Sarcopterygians (fleshy fins) and actinopterygians (ray fins) differ in the skeletal structure of the _____.

fin

Actinopterygian, idealized fin structure

a highly flexible, fan-like arrangement of dermal skeletal elements, designed for precise hydrodynamic control.

Sarcopterygian (lungfish) fin structure

fleshy, muscular fin lobes supported by a central bony axis

Lepidotrichia, a synapomorphy of Osteichthyes, support the fin webbing to allow…

precise movements of the fins using muscles at the base of each fin ray

bony lepidotrichial segments

a synapomorphy of Osteichthyes

All have functional lungs used

for respiration. Amia (Bowfin) was used

to demonstrate that lungs

oxygenate the heart muscle by

Colleen Farmer.

Extant non-teleost actinopterygian fishes

All non-teleost Actinoptergyii have functional lungs. The

lungs have become the swim bladder in _______.

Teleostei

Acipenseriformes

Paddlefish and sturgeon; Source of caviar

The chinese paddlefish was declared ______ in 2020.

extinct

___________ of eastern Europe and Asia among the world’s largest fishes and a source of expensive caviar.

beluga sturgeon

The rostrum of paddlefish has densely packed _______ for

electroreception between the intricate stellate bones.

ampullae

In non-Teleost ________, e.g. Amia, the maxilla is mobile but the premaxilla is not

Neopterygii

In _______, the lungs evolved into a gas bladder used for buoyancy, the tail is homocercal, and the premaxilla of the jaws is also mobile, for greater diversity of feeding function.

Teleostei

Teleostei synapomorphies

Homocercal caudal fin, mobile premaxilla, lung evolves into gas bladder

Elopomorpha share what?

leptocephalus larvae

________ include eels and tarpon, and all have leptocephalus larvae that can be transparent

Elopomorphs

________ have specialized pharyngeal jaws they can protrude into the mouth

Moray eels

How do leptocephalus larvae survive without red blood cells?

thin, so they can rely on diffusion, not super active (don’t require lots of oxygen)

Otocephala united by presence of

Weberian apparatus- uses the swim bladder as an ear

Otocephalans include more than _______ extant species

10,000

Synapomorphy of Otophysans transmits _________ to the inner ear from the swim bladder, which acts like a microphone.

vibration (sound)

Otophysans have an apparatus that uses the ________ as an ear

swim bladder

Euteleostei includes most species of Teleostei, more than ______ extant species

17,500

Archerfish, a type of Eutelostei

renowned for "shooting down" land-based insects resting on overhanging branches by precisely spitting high-velocity water jets from their mouths.

Convergently evolved body shape in pike, gar, and barracuda allows ______

rapid strikes

Eels (and many fish) swim by…

essentially using its body as a series of paddles. Their body pushes against the water, producing a forward thrust, leaving a wake behind.

*Anguilliform*

Anguilliform swimming movement.

Eels and spiny dogfish. use their body to create thrust.

Carangiform swimming movement

some of the body is evolved, less than half, mostly the tail.

Examples of fish that use Carangiforms

Jack and Herring

Thunniform swimming movement

Little body bending and tail produces most the thrust.

What fish use thunniform swimming movements

Tuna and White shark

Labriform swimming movement

uses pectoral fins to create thrust most of the time.

What fish use labriform swimming movement?

Wrasse and Surfpech

Spawning and parental care by oviparous ray-finned fishes is

varied

Male seahorses ______ the eggs

brood

Sex determination in teleosts

A) Gonochorism in scissortail seagent-major

• Immature fish grow to either male or female, DO NOT CHANGE SEX

B) Protandrous Hermaphroditism in clown anemonefish

• Immature fish → male → female

C) Protogynous Hermaphroditism in bluehead wrasse

• Immature fish → initial phase male or female → terminal phase male

D) Simultaneous Hermaphroditism in harlequin sea bass

• alternate male and female roles during spawning.

Gonochorism

Immature fish→ either male or female

DO NOT CHANGE SEX

-scissortail

Protandrous Hermaphroditism

• Immature fish → male → female

-clownfish

“first-male”

Protogynous Hermaphroditism

• Immature fish → initial phase male or female → terminal phase male

-bluehead wrasse

“first female”

Simultaneous Hermaphroditism

such as the harlequin bass

-alternate male and female roles during spawning.

__________ teleosts change sex depending on conditions.

Hermaphroditic

About 88% of teleosts are

gonochoristic, meaning that their

sex does not change during life.

Life zones of the deep sea

Bathypelagic- 1000- 6,000+ meters

Aphotic- 1,000- 4,000 meters

Bathypelagic fishes

life without sunlight

Specializations in bathypelagic fishes (below 1000 m)

Large mouths and stomachs

Light organs

Sensory systems.

Bathypelagic Light organs

Many deep-sea fishes have light-producing photophores

arranged on their bodies in species-specific and even sex-specific

patterns. The light is produced by symbiotic species of Photobacterium

and bacteria related to Vibrio. Photophores attract prey or act as signals

to potential mates in the darkness.

Bathypelagic Large mouths and stomachs

If a fish rarely encounters potential

prey, then it should have: (1) a mouth large enough to engulf nearly

anything it does meet; and (2) a gut that can expand to accommodate

nearly any meal.

Bathypelagic Sensory systems.

Because of the perpetual dark of their habitat, adults

of many species of deep-sea fishes have reduced eyes or

non-image-forming eyes that merely detect light. Other fishes that live

on bottom of the deep sea rely primarily on touch and chemosensation

to detect prey.

Male deep-sea anglerfish become parasitic. why?

to solve an extreme survival problem: finding and securing a mate in the pitch-dark, sparsely populated bathypelagic zone

One trend in the evolution of teleost jaws is

a greater degree of jaw protrusion, involving both

the maxilla and the premaxilla

Sling jaw wrasse

an extreme adaptation of protrusible jaws, the longest of any fish for its size

Lionfish

Have spines with powerful neurotoxins