Ichthyology Exam Final

Two smallest fishes in the world are in these two families

Gobiidae and Cyprinidae

Ctenoid scales, modified pectorals into arms, illicium

Atennaridae

What is a biochrome?

biological pigmented cells

What is a schematochrome?

light reflecting from structures rather than pigments, light reflecting from specialized chromatophores with crystals

Types of biochromes

melanophores, erythrophores, xanthophores, leucophores, iridiophores

melanophores

black or brown pigment produced by melanin

erythrophores

red pigment produced by carotenoids and pteridines

xanthophores

yellow pigment produced by carotenoids

leucophores

white pigment produced by purines (guanines and hypoxanthine)

iridiophores

iridescence produced by purines (guanine)

chromatophores

pigment producers

types of chromatophores

biochromes and schematochromes

physiological color change

short term color change that happens quickly and is controlled by nervous system

morphological color change

long term color change that happens slowly and is controlled by endocrine system

channel catfish taxonomy from family up

Ictaluridae, Siliuriformes, Otophysi, Ostariophysians, Otocephala, Teleostei, Teleomorpha, Holostei, Actinopterygii, Osteichthyes, Gnathostomata, Craniata

Single gill covering, cartilaginous, upper jaw fused to cranium, head claspers

chimaeridae

What are the synapomorphies (shared traits) for Otsariophysians?

Schrecktoffs substance, breeding tubercules, webarian ossicles

Subdivision elopomorpha, elongate body, sargasso sea for reproduction, leptocephalis larvae

anguillidae

What does intermediate superorders mean?

orders with derived and primitive traits

examples of intermediate superorders

paracanthopterygii, cyclosquamata, stomiiformes

Why is more appropriate to group sharks with teleosts than with lampreys?

teleosts and elasmobranchs have jaws and paired fins

Are fishes monophyletic or paraphyletic group? Why?

paraphyletic because we do not include all the sarcopterygians in the lineage which include tetrapods

Advanced teleost characteristics

toothless maxilla, jugular pelvic fins, vertical pectoral fins, physoclistous swim bladder, two dorsal fins, spines

List features that differentiate elasmobranchs and teleosts

cartilage vs. bony, gill slits v opercula, solid cartilage cranium vs. bony plates in cranium

What is a protandrous hermaphrodite?

a fish that is male first then turns female later in its life

Breeding tubercules, Schrechtoffs substance, Webarian ossicles, most common Louisiana family

Leuscicidae

List four of the five extant classes that contain fishes

myxini, petromyzontimorpha, chondrichthyes, osteichthyes

What is a secondary sex characteristic?

characteristics associated with reproduction, but is not required for reproduction to occur

Elongated body and jaws, physostomous swim bladder, spiral valve intensine, ganoid scales

Lepisosteidae

Plate skinned, ball and socket skeleton, dorso-ventrally compressed, small in size, partially ossified endoskeleton

placoderm

What is the rete mirabile?

wonderful net, uses counter current exchange in blood flow

Where is the rete mirabile located?

in the gills

poster colors

territoriality, schooling behavior, intra-specific communication, predator confusion, aposematic, advertising colors

aposematic

advertisement of danger

disruptive coloration

color patterns that interfere normal fish body shape

camoflauge

blend into the environment as well as possible

lateral line stripe

used for orientation, common in schooling species, confuses predators

oscelas

eye spot on posterior end of fish

countershading

dark coloration on dorsal side, bright coloration of ventral side

polychromatism

different colors in different individuals, associated with different life stages in fishes

types of communication

visual, electrical, chemical, bioluminescence, auditory

visual communication

certain colors associated with breeding, shows relative fitness of male

electrical communication

ability to communicate through turbid water, special muscles contract to send electricity, evolved independently throughout the tree of life

chemical communication

pheromones for social hierarchy, schrektoffs substance - warning signal

bioluminescence

ability to produce light, mostly associated with deepwater species, symbiotic relationship OR chemical reaction through luciferase

auditory communication

stridulation, grinding of teeth, vibrating muscles and swim bladder, bone to bone contact

stridulation

production of sound by rubbing body parts together

why do particular species occur where they do?

evolved in an area, dispersal

number of marine species

14915

number of freshwater species

14547

number of euryhaline

2985

total number of fish species

32447

available freshwater habitat

35 million km^3, 2.5% of available habitat

available salt water habitat

1.365 billion km^3, 97.5% of available habitat

Why are there so many freshwater species?

allopatric speciation, unstable habitats, restricted distribution

euryhaline marine fishes

primarily marine fishes capable of entering freshwater

obligatory freshwater fishes

must spend at least part of their life cycle in freshwater

saltwater dispersants

species capable of dispersing long distances in saltwater

freshwater dispersants

freshwater representatives of marine groups, incapable of saltwater dispersal, reliant on freshwater routes

primary freshwater dispersants

species only occurring in freshwater

secondary freshwater dispersants

euryhaline species in brackish water

freshwater biogeography regions

ethiopian, neotropical, oriental, palaearctic, nearctic, australian

ethiopian region

most of Africa and parts of the middle east

fishes of the ethiopian region

2000 freshwater species, ostariophysians biggest group, morymids, polypteridae, lungfishes, osteoglossidae, cichlids

neotropical region

south america, south and central mexico, parts of the caribbean, central america

fishes of the neotropical

over 3600 species, mostly catfishes and charchins, many ostariophysians, no cyprinids, SA over 1200 catfishes and characins, 100 to 150 species of cichlids

oriental region

peninsula of India and southeast Asia, poorly studied region

fishes of the oriental region

300 species, cyprinids and some catfishes (clariids), snakeheads, gouramis, knifefishes, and synbranchid eels

palaearctic region

northern most freshwater biogeographic region

fishes of the palaearctic region

cyprinids and cobitids, 17% anadromous, perches, killifish, esocids

Lake Baikal

1/5 of the world's freshwater, 36 species of sculpin

nearctic region

between tropics and palaearctic, divided into three subregions, glaciation impacted fish distribution

fishes of the nearctic

950 native species, minnows, percids, suckers, ictalurids, and sunfishes, 11% diadromous, 6% euryhaline

atlantic subregion

drainage to Gulf of Mexico or Atlantic Ocean, hiodontidae

pacific subregion

drainage to pacific ocean, Rocky Mountains split

mexican subregion

transitional, northern portion dominated by similar species to Mississippi River, southern portion dominated by similar species to neotropical region, central highland area holds many endemic species

Australian region

australia and new zealand

fishes of the Australian region

lungfish, bony tongue (barramundi), no cyprinids, lampreys, anguillids, galaxids, gobies silversides,snooks, rainbow fishes (melanotaenidae) endemic

endemic

small geographic range

cosmopolitan

wide geographic range

continental drift

Pangea 225 mya, north and south continents of Laurasia and Gondwanaina 135 mya, current day separation 65mya

areas of the marine benthic realm

continental shelf, supra-littoral, littoral, sublittoral, continental slope, abyssal and hadal

continental shelf

0m to 200m, contains supralittoral, littoral, and sublittoral zones

supralittoral/ littoral zone

splash zone, intertidal area, species in rocky erosional zone or sandy depositional zone

sublittoral zone

more stable than intertidal, richest fauna associated with reefs and kelp forests, anuillid eels, pipefishes, drums and scorpion fish, outer area productive and used for commercial fisheries

continental slope

extends to 200-3000m, contains upper and lower slopes, light levels diminish at 750 to 1000m, low temps, little water movement, "pelagic rain"

upper slope

200 - 1000m, rockfishes, cod, hake, little water movement

lower slope

1,000 - 3,000m, chimaeriform body common, cusk eels, squalid sharks

abyssal and hadal zone

3000-6000m, >6000m, cold, completely dark, low nutrient base, fishes have vestigal eyes, some lack pigmentation, neuromasts often on stalks, very few known fishes

marine zoogeographic regions

divided into broad latitudinal zone based primarily on temperature, Indo-Pacific, western Atlantic, eastern Pacific, eastern Atlantic, north temperate, south temperate, arctic, anarctic

Indo-Pacific

most extensive and diverse zoogeographic region (4,500 species), shelf running from western Australia to eastern Africa

Western Atlantic

encompasses a large shelf, fish groups (particularly reef dwellers) converge with Indo-Pacific (1500 species), outlet of Amazon River can divide some northern and southern populations

Eastern Pacific

narrow band of South American coast, low diversity due to a paucity of islands and reefs (750 species), share species with western Atlantic due to historical connection before uplift of Isthmus of Panama

Eastern Atlantic

narrow band along African coast, less diverse due to paucity of island and reefs (450 species), share species with Indo-Pacific due to movement around tip of Africa

North Temperate

temperature based designations, Mediterranean Atlantic, Asian Pacific, North American Atlantic and Pacific

South Temperate

southern edges of South American, south Africa, Australian

Arctic

links fauna of surrounding continents and includes circumpolar species

Anarctic

shares few species with south temperate region, though many tax indicate distant connections

Pelagic regions

latitudinal belts encircling the globe, arctic, subarctic, temperate, subtropical, tropical, anarctic

Circumtropical species

genera found in tropical belts around the world, example needlefish found around the world in isolated areas with specific groups of species