Aquatics K3: Organisms (minus macroinvertebrate ID)

nares

Similar to nostrils, but used for smelling only (no breathing)

Operculum

Bony flap that protects the gills from harm. Opens and closes to allow water to pass over the gills

Pectoral Fin

Allows for abrupt changes in side-to-side direction and speed. Brake to decrease speed while swimming.

Pelvic Fin

Stabilizes fish while swimming and allows for up-and-down movement in the water.

Vent

Removes waste and extra water. Outlet for eggs or milt (sperm) during spawning. 

Anal Fin

Stabilizes fish while swimming

Caudal Fin

Moves, propels, or pushes the fish through the water.

Adipose Fin

not present on a lot of fish species. Unknown purpose. Trout, salmon, and catfish have an adipose fin. Small thick, fleshy fin located between dorsal and caudal fins

Dorsal Fin

Maintain balance while swimming

Barbels

“Whiskers” found on the head area of fish such as catfish or bullheads. Sensory organ to help track down prey or food. Sturgeon also have barbels.

Swim Bladder

Long, skinny organ that can inflate/deflate with air to allow fish to swim at different levels in the water column.

otoliths

Fish have pairs of inner ear bones called otoliths that allow them to sense sounds in the water. Fisheries biologists can also use otoliths to age fish and determine the health of fish populations.

Lateral line

Senses vibrations or movements in the water. Allows fish to locate predators and find prey.

white crappie (Pomoxis annularis)

Black Crappie (Pomosix nigromaculatus)

how to tell difference b/w white and black crappie

white: 5-6 spines on dorsal fin

black: 7-8 spines on dorsal fin; more deeper-bodied than white crappie

“Blackstripe” or “blacknose” crappies; genetic color variation of black crappie with a distinctive dark strip from top dorsal fin to under mouth

Largemouth Bass (Micropterus slamoides)

Two subspecies in Mississippi

Northern Largemouth bass (Micropterus salmoides salmoides) native to MS

Florida Largemouth bass (Micropterus salmoides floridanus) was introduced

MISSISSIPPI's STATE FISH

Spotted Bass (Micropterus punctulatus)

Bluegill (Lepomis macrochirus)

Channel Catfish (Ictalurus punctatus)

Shovelnose Sturgeon (Scaphirhynchus platorynchus)

listed as threatened due to similar appearance with endangered pallid sturgeon

Diadromous fishes

describe species that spend part of their lives in freshwater and part in saltwater

• Two categories of diadromous fishes: Catadromous and anadromous

Catadromous fishes

hatch/born in marine habitats, but migrate to freshwater areas to spend the majority of their lives maturing/growing → return to sea to spawn

• Catadromous “downward-running”

Anadromous fishes

 hatch/juvenile in freshwater → migrate to mature in ocean → migrate back up rivers to reproduce in freshwater habitats

• Anadromous “upward-running”

Freshwater fish are hyperosmotic to the environment

• Actively take ions across gills and skin using energy

• Excrete nitrogenous waste products in great quantities (highly diluted urine) to rid excess water

Marine Fishes lose water to ocean and gain ions from it

increase their drinking rate & extrete smaller amounts of highly concentrated urine

Eliminate excess ions through specialized salt-excretion cells in gills and in lining of mouth

Factors that are decreasing the population of anadromous species

• Estuarine habitats are under threat

• Increased river pollution damages critical spawning habitats

• Building of dams or man-made barriers makes upward migration difficult

• Overfishing of commercially important species

biomonitoring

Biomonitoring is the use of organisms to assess the overall quality of their environment or habitat

why do we use macroinvertebrates for WQ and biomonitoring?

Macroinvertebrates are better reflections of long-term water quality compared to single chemical sample b/c they have limited mobility and cannot escape pollution

What affects macroinvertebrate communities?

Streamflow, geology, elevation, temperature, dissolved oxygen, seasonal life cycle patterns, substrate, and riparian habitat influence abundance and diversity of macroinvertebrates

how do humans affect macroinvertebrate communities?

Human changes: increased pollution, land use changes that modify channel structure or contribute to nonpoint source into waterbody

Macroinvertebrate multimetric index (MMI)

Macroinvertebrate multimetric index (MMI) is a numerical value calculated by combining individual measurements (metrics) of a sample into an overall index score

What are the challenges of using macroinvertebrates as a water quality parameter?

Ensuring consistency in collecting samples

Taking appropriate sample sizes

Conducting adequate research

Special considerations — multiple pollutants can affect macroinvertebrates

Hemimetabolous

(incomplete metamorphosis) Orders Ephyemeroptera, Plecoptera, and Odonata

• Go from egg to larva (nymph) to adult with no pupal stage → nymphs look very similar to adults

Holometabolous

(complete metamorphosis w/ a pupal stage)

• Orders Trichoptera, Coleoptera, Megaloptera, and Diptera

• Egg → larva → pupa → adult

• Larvae look very different from adults

5 aquatic insect habitats in stream systems

Riffles, pools, substrate, vascular plants, and woody debris

how do aquatic insects breathe

Tracheae tubes take oxygen through openings in the cuticle (protective covering) called spiracles and carry it directly to the body tissue

• Lotic aquatic systems typically pull oxygen from the dissolved oxygen in the water around them

  • Typically have closed tracheal systems → no spiracles/openings present in cuticle, only some thinner areas of the cuticle

Alligator Weed (Alternanthera philoxeroides)

• Non-native; originally from South America and first reported in Alabama in late 1800s

  • Form at the shoreline in thick mats

American Lotus (Nelumbo Lutea)

native plant

Salvinia (Salvinia spp)

Common salvinia (Salvinia minima) and giant salvinia (Salvinia molesta) are non-native invasive plant species

Water Hyacinth (Pontederia crassipes)

• Non-native, highly invasive species from Brazil

Water Lily (Nymphae spp)

Some species are native, while others are cultivars or introduced from elsewhere