• There are a range of marine plants and animals

Marine Macrophytes

• These include seagrasses, macro-algae and mangroves.
• Seaweeds (macroalgae) are multicellular, photoautotrophic, non-plants requiring light, nutrients, and a substrate for attachment, reproducing sexually or asexually through fragmentation.

Ochrophyta

• These are red algae.
• Approximately 1500 species exist with 99.7% being marine.
• They are the largest algal species with tough, thick blades/stipes.
• Kelp is an example.
• Pneumatocysts (gas-filled floats) are unique to this species, found in Sargassum and Ascophyllum, bringing algae to the surface for optimal photosynthesis.
• Pigments include chlorophyll A and C, xanthophylls, and fucoxanthin.
• Distribution ranges from intertidal to subtidal zones.

Rhodophyta

• These are red algae.
• There are approximately 4000 species, with 98% being marine.
• They have small, thin tissues, with some coralline algae exhibiting calcification, making identification difficult.
• Pigments include chlorophyll a, phycobilins, and phycoerythrin, capable of being fully bleached.
• Distribution is intertidal to subtidal, tending to be found deeper than other algae.

Chlorophyta

• These are green algae.
• There are about 7000 species, with 13% being marine.
• They have small, thin tissues.
• Examples include Ulva lactuca and Chaetomorpha spiralisis.
• Pigments include chlorophyll A and B, appearing bright and dark green.
• Distribution ranges from the splash zone to shallow subtidal areas.

Anthophyta

• These are flowering plants

Pigments and Depth Distribution

• Chlorophyta transitions to ochrophyta, then rhodophyta with increasing depth.
• Light penetration varies with wavelength.
• Red light is absorbed fastest in the oceans.
• Fucoxanthin absorbs yellows, blues, and greens most effectively.
• Phycoerythrin absorbs greens and yellows the most effectively.

Human Use of Algae

• Algae is used for direct consumption and as thickening/stabilizing agents (alginate, agar, carrageenan), as well as in packing materials and aquaculture.

Algae

• Algae structures include blades, stipes, heptera, and holdfasts.
• Blades are responsible for photosynthesis and nutrient absorption.
• Holdfasts provide attachment to the substrate.
• Nutrients are absorbed directly into the tissue from the water.
• Internal transport occurs via diffusion.
• Specialized cells produce spores and gametes.

Plants

• Plant structures include leaves, roots, rhizomes, and flowers.
• Roots absorb water and nutrients.
• A vascular system with xylem and phloem facilitates internal transport.
• Flowers facilitate sexual reproduction.

Submerged Plants: Seagrasses

• There are approximately 60 species that are low-intertidal to 50m (usually < 10m).
• Three species common to the US include Thalassia, Zostera, and Phyllospadix.
• Asexual reproduction (vegetative) occurs with new vertical roots growing off horizontal rhizomes.
• Sexual reproduction involves large pollen grains transported by water currents.

Seagrass Habitat

• Epibionts (organisms on the surface of algae, algae and invertebrates) include filamentous algae, snails, calcifying worms, anemones, bryozoans, etc.
• Deposit feeders consuming lots of silt/detritus include sea cucumbers.
• They are a megafauna food source for manatees, dugongs, and turtles.
• They offer protection from predators like the cunner seahorse.
• They provide nursery habitats where juvenile scallops settle onto grass.

Emergent Plants

• These include salt-tolerant terrestrial plants, salt marsh plants, and mangroves.
• They form a boundary habitat able to live in fresh or salt water, with terrestrial communities above the water line at low tide and marine communities below the water line at high tide.

Distribution

• Mangroves tend to be in tropical areas.
• Salt marshes tend to be in more temperate and polar areas.
• Warmer environments vary, but seagrasses start to dominate once it's too cold for mangroves.

Salt Marsh

• A variety of plants live at different elevations due to salt tolerance; plants with high tolerance found in lower intertidal and plants with low tolerance found in higher intertidal.

Spartina alterniflora

• It dominates low marsh, exudes salt crystals from leaves, and provides food in salt marshes of South Carolina.

Mangroves/Manga

• These are an ecological grouping.
• They have a tree-like anatomy : anchoring and aerial roots absorb freshwater during storm events and provide holding structure; pneumatophores bring oxygen to the roots.
• Reproduction occurs via leaves, fruits, and seedlings, sprouting and becoming a seedling on the tree, anchoring deeper into the water with insect or bird pollination.

Plants of FL and Caribbean Mangroves

• Rhizophora mangle (red mangrove) is the most salt-tolerant, with prop roots and the ability to exude salt.
• Avicennia germinans (black mangrove) has pneumatophores, extending to Louisiana where it coexists with Spartina.
• Laguncularia racemosa (white mangrove) is rarely inundated.
• Animals include coral, sponges, oysters, reef fish, and pelicans, with habitats above and below the tide.

Similarities in Marine Plant Ecosystems

• Habitat-forming species stabilize sediments and hard substrates.
• They provide food in the form of detritus, offer cover, and serve as nursery habitats.
• They offer shoreline protection.
• They breaks wave energy, forming a water-absorbing buffer zone.

Threats to Emergent Plant Habitats

• Development such as aquaculture, housing, and tourism threaten these ecosystems, resulting in loss of habitat/nursery areas and shoreline protection.

Benthos

• Consists of Porifera, Cnidaria, Ascidiacea, Mollusca, Arthropoda, and Bryozoa.
• The benthos is the largest habitat on the planet in aerial coverage, with 83% of the habitat deeper than 1000m.
• There is a high diversity of species.
• It is the most diverse in coral reefs and unique (hydrothermal vent community) habitats on earth.

Major Roles

• The benthos plays a role in climate regulation via carbon sequestration; carbon and nutrient cycling; protein for human consumption; and absorbing and diluting pollutants.

Physical/Chemical Features of Benthic Habitats with Depth:

• Supralittoral (Splash) Zone has spray, maximal light level, largely mimics variations in the atmosphere temperature variation, only during severe storms water turbulence, very high salinity variation.
• Littoral (Intertidal) Zone has varies with wind and tidal state water effects, dependent upon tidal state (usually high) light level, varies with tidal state temperature variation, normally strong water turbulence, high (dependent upon tidal state) salinity variation, highly variable.
• Sublittoral (Subtidal) Zone has continuous water effects, depth-related (generally high to minimal) light level, minimal temperature variation, varies according with depth water turbulence, small salinity variation, variable.
• Bathyl Zone has continuous water effects, depth-related (minimal to none) light level, minimal temperature variation, generally minimal water turbulence, very small salinity variation, constant.
• Abyssal Zone has continuous water effects, none light level, minimal temperature variation, generally minimal water turbulence, very small salinity variation, constant.
• Size ranges from megafauna, macrofauna, meiofauna, to microfauna
• Lifestyle can be epifaunal or infaunal.

Feeding

• Epifaunal Mobile species are Amphipods (Filter Feeders), Snails and Crabs (Deposit Feeders), Snails and Sea urchins (Herbivores), and Snails, Crabs, and Seastars (Carnivores}.
• Epifaunal Sedentary species are Clams/Mussels (Filter Feeders),
• Epifaunal Attached/Sessile species are Sponges, Clams, Worms, and Ascidians (Filter Feeders), Sea Anemones (Carnivores), and Corals.
• Infaunal Mobile species are Worms (Filter Feeders/Deposit Feeders/Herbivores), and Snails, Shrimp, and Sea Anemones (Carnivores).
• Infaunal Sedentary species are Clams (Deposit Feeders.
• Infaunal Attached/Sessile species are Amphipods and Clams (Deposit Feeders).

Deposit Feeders

• Deposit feeders feed on sediment and organic matter(OM) within the sediments.
• An example is the sea cucumber.

Herbivores

• Herbivores graze on macroalgae, seagrasses, or benthic microalgae.

Carnivore/Scavenger

• These organisms seize and capture live prey, feeding on dead decaying tissue.

Suspension Feeders

• Suspension feeders collect particles from the water column and are very diverse
• Feeding types include mucus-bag, tentacle-mucus, ciliary mucus, and setose feeding

Habitats

• Soft-bottom habitats are physically unstable, most animals are infaunal (live within the sediments), most animals feed on the sediments (deposit-feeders), macroalgae are uncommon, abundance of solitary organisms, generally small animals, and animals tend to be soft-bodied.
• Hard-bottom habitats are physically stable, most animals are epifaunal (live on the surface), most animals feed on materials in the water column (suspension-feeders), macroalgae are generally present with sufficient light levels, colonial organisms are common, typically large animals, and animals are commonly calcified.

Morphological Adaptations of Hard-Bottom Organisms

• Adaptation of short/squat profiles to minimize stress
• Stout or rigid supported structures (e.g., oysters)
• Structures presenting extensibility
• Presence of holdfast/byssus (e.g., kelp and mussels)

Avoiding Dessication

• Morphological adaptations include calcification, thick skin/cuticles, modification of shell shape/color, and the ability to isolate tissues from the external environment.
• Temperate regions have darker colors than the tropics to maximize light absorption.
• Physiological adaptations include enzymatic and physiological mechanisms to cope with thermal stress.

Adaptations to Soft-Substrate Habitats

• Behavioral adaptations include homing behavior (limpet snails) and larval settlement patterns (aggregation behavior).
• Physiological adaptations involve moving through sediments with thin, elongated, flexible bodies, and retaining contact with the sediment-water interface.
• Morphological adaptations include feeding appendages (siphons, palps, tentacles).
• Behavioral adaptations involve tube-making activities, permanent and semi-permanent burrows to the sediment-water interface.

Living in an Anoxic World

• Organisms in these environments will form toxic hydrogen-sulfate sediments with morphological adaptations including thick skins and shells, feeding appendages to the surface (reduces SA of org. to hydrogen-sulfide).
• Behavioral adaptations include tube-building and burrows to the sediment-water interface (creating boundary layers all around).
• Physiological adaptations include anaerobic respiration capabilities, oxygen-binding compounds in blood (why marshes smell bad).

Benthic Life Cycle

• They have Bipartate life cycle with broadcast spawning.
• They have Brooding (fertilization inside organism where larvae exit organism to free swim)
• They have Direct development- embryo in egg case (up to juvenile)
• Stays benthic

Larvae

• Lecithotrophic larvae do not feed; they spend a short time.
• The yolk sac of energy is provided by the parent.
• Example- coral larvae
• Planktonic larvae feed while in several planktonic stages; it spends up to weeks or months

Large Scale Animal Characterization

• There are different levels of cellular organization.
• Porifera have specialized cells not really working together.
• Cnidaria and Ctenophora have specialized tissues.
• All other organisms have organs.
• Symmetry : Porifera- asymmetrical.
• Cnidaria and Ctenophora- radial; ctenophores derived bilateral.
• All other organisms- bilateral.
• Echinoderms have radial symmetry derived as an adult.

• of embryo cell layers - both have endoderm and ectoderm.

• Diploblast - extracellular layer of proteins and carbohydrates.
• Triploblast- 3rd cell layer called the mesoderm.
• Porifera- N/A.
• Cnidaria and Ctenophora- diploblastic.
• All other organisms - triploblastic.
• Protostome (mouth; spiral) vs. deuterostome (anus; radial).
• Only happens to triploblasts.

Phylum Porifera (Sponges)

• There is no definite symmetry, all are sessile.
• Multicellular, no tissues, no organs, no body cavity, no NS.
• Simple vs complex sponges.
• Complex sponges have choanocytes (collar-cells) chambers for filter-feeding.
• Food particles are trapped in the collar-cell when flagella moves water current.
• Water is moved into sponge through pores (ostia) and exit through osculum.

Cell Types

• Pinacocytes- flattened epidermal cells.
• Porocytes - tube-like pore cells that let in water.
• Choanocytes- flagella create current and trap food.
• Amebocytes- wanderer, secrete “skeletal components", sponge stem cells:
• Calcareous , Siliceous spicules and Spongin
• They reproduce sexually or asexually.
• Physical branching or budding.
• Gametes produces by choanocytes or amebocytes.
• Planktonic larvae .
• They live in aquatic environments; most marine.Sperm → egg → settlement and metamorphosis → adult .
• Class Calcarea - CaCo3 spicules
• Class Hexactinellida- glass; siliceous spicules
• Class Demospongiae- most common; siliceous spicules and spongin

Phylum Cnidaria

• These have Radial symmetry, and are Multicellular, tissues, organelles (nerve nets, nematocysts) , diploblast,Internal cavity and mouth.
• They can be polyp or medusa
• Endodermis, gastrodermis, gastrovascular cavity, tentacles.
• Aquatic; most marine.
• Mostly carnivores, some filter feed, symbiotic algae.
• Cassiopea upside-down jellies.
• Lots of photosynthetic algae in cells providing food and growth
• Painful nematocysts
• Asexual (budding) or sexual reproduction (planktonic larvae).

Classes

• Class Scyphozoa, Class Cubozoa, Class Hydrozoa - hydroids, siphonophores, hydroids are benthic.
• Feathery colonies of many polyps; specialization among the polyps, Alternate w/ dominate polyp stage and reproductive medusa

Class Anthozoan

• These are anemones.
• These are solitary or colonial polyps, Lack medusa stage, Largest polyp cnidarians.
• Gut partitioning - septa; increase gut SA and structural support.

Anthozoan Divisions

• Octocorals- Soft corals, gorgonians, sea fans, sea pens, ~ around 2,000 spp., Have 8 pinnate tentacles and 8 septa.
• Tanned collagen endoskeleton (forms in mesoglea); made of OM. Hexacorals - sea anemones and stony corals, 4,000 spp.
• More than 8 tentacles and septae (usually multiples of 12), Massive carbonate exoskeleton (secreted by endodermis). Reef corals (hermatypic).
• Polyps produce CaCO3 skeleton, Nearly all have symbiotic zooxanthellae, Settle on specific algae.

Phylum Annelida

• It is segmented worms
• Bilateral, triploblastic, protostome, Marine, freshwater, terrestrial.
• Nephridium and parapodia: repeat on each segment, Advanced tissues and systems (brain, closed circulatory system), Advanced body organization- cephalization (where main sensory organs are concentrated)

Class Polychaeta

• Lots of variation (errant worm- mobile, xmas tree worms-sessile, sedentary worms).
• Carnivores, deposit or suspension feeders depend on mobility, some feed in hydrothermal vent communities.
• Other worms.

Other Worms

• Platyhelminthes, Nemertea, Nematoda, Gastrotricha, Kinorhyncha Phylum Mollusca
• More species in ocean than any other group. Bilateral, triploblast, protostome, Mantle, foot, visceral mass. Muscular foot for locomotion, Visceral mass contains digestive system.
• Mantle protects visceral mass and secretes a shell (CaCo3 shell), Radula; made of chitin- runs along the surface floor to scrape in mouth, Highly developed sensory organs. Class Polyplacophora (chitons).
• 8 shell plates/valves, Mostly herbivores; few carnivore and omnivore, Exclusively marine, Broad foot attached over broad area - very hard to pry off.

Class Gastropoda (Snails)

Largest, most common, most varied, Around 75,000 spp, most marine.

• Single shell, Reduced or absent in some spp., Not lots of ornamentation (harder to eat). Torsion- top of snail rotated 180 degrees over generations . Allows entire body to retreat into shell completely. Closes with calcified sheet (operculum) on posterior end.

Feeding Styles

• Herbivores- feed on primary producer.
• Nudibranch feed on algae and steal their chloroplast and continue to undergo photosynthesis (kleptoplasty).
• Cone shell; predatory snails have pointed shells, Conch shells. Radula-boarding holes (circular shaped), on clams and mussels.

Class Bivalvia (Clams, Mussels, Scallops)

• Lateral compressed body, enclosed in 2 shells/valves, No true head or radula. Ctenidia- expanded and folded gills used for gas exchange, Filtration and sorting food particles (mucus and cilia trap food).

Lifestyles

• Byssal threads - mussels -Sedentary; epifaunal -Mussel can excrete new threads Cementers - oyster Sessile, Attach by CaCo3 blue, Swimmers - scallops - Have light-sensing organs, Claps shells on sides, filter feeder. Burrowing - clams - Shallow or deep, Can burrow into hard substrates like sandstone. Borers - shipworms, Very reduced shell bores into wood, Big problem back then , Do not eat wood; just use as place to live Class cephalopoda (octopus, squid, nautilus). tentacles/arms instead of foot Well developed sensory organs (large brains) Loss of shell (most), Nautiluses have heavy shells (buoyancy helps to swim).
• Squid shell reduced internally to peri, Cuttlefish have large CaCO3 inside body, Octopus lost shell completely Carnivores
• Catch prey through camouflage using chromatophores in skin to blend in, Blend with patterns of substrate

Phylum Arthropoda

• Bilateral, triploblastic, protostome, Largest phylum, ¼ animal spp, many in terrestrial less in marine, Segmented, flexible body plan (jointed appendages). Tagmatization- fusion of segments; caripase- actual fusion, Head, thorax, abdomen, Cephalothorax, abdomen,

Organ Systems

• Advanced tissue and organ systems, Specialized sensory receptors and high degree of cephalization, Simple or compound eyes, Antennae, Appendage specialization- swimming, crawling, feeding, attachment, mating (gills on inside of some appendages), Acellular external skeleton (exoskeleton)- composed of chitin .
• Molting, crawls backwards, feeds on shell, Size limitation- can the shell crash on the org?, Some only have determinate molt stage , Largest arthropods found in marine environment. Superclass Crustacea, 68,000 described spp (3x undescribed).

Features

• Most marine, Chitinous exoskeleton hardened by CaCO3, Most have gills for aqueous gas exchange, Egg → zoea → megalopa → juvenile crab → adult crab with molting, Mobility- swimmers, walkers, sessile.

Feeding Styles

• Filter feed, scavengers, carnivores.
• Hermit crabs are scavengers Barnacles are filter feeders

Marine Orders

• Order Decapoda (shrimps, lobsters, crabs)
• 10-legged (5 pair) crustaceans; largest group (>10,000 spp)
• Largest in size- +2m in leg span in some (Japanese deep sea spider crab, coconut crab)
• Challiped claws for grabbing food
• Small crustaceans- copepods, euphausiids, barnacles, amphipods, isopods
• Barnacles Filter-feeders (some are highly modified parisities)
• Lives on crab and steals nutrients; crabs cannot molt or reproduce
• 12 ciri hairs pull food through currents Sexual reproduction with characteristic crustacean larvae
• Order Amphipoda, Curved, laterally flattened body
• Most under 2 cm, Deep sea gigantism
• Appendages specialized to functional niche (swimming, feeding), Free-living and parasitic
• Most detritivores, Some herbivore, carnivore, and omnivores
• Class Caprellidae and Gammaridae, Order Isopoda (pillbugs)
• Body dorsoventrally flattened (flat back), Areas of more basic soils bc of CaCO3 shell, Found in habitats as amphipods walk/crawl, Free-living and parasitic
• Detritivores, herbivores, filter feed, carnivores

Chelicerata (Horseshoe Crab)

• Subphylum Chelicerata, Class Xiphosura (horseshoe crab)
• NOT crustacea, No CaCO3, Primitive arthropod relatively unchanged for >200 my, Long-lived
• Ecologically important, Feed on worms/clams/small fish?/crustaceans?, Mouth in middle of legs
• Medically and commercially important, Bait in fisheries, Hemolymph (blue colored blood) is very sensitive to endotoxin. Subtance produced by a gram-negative formula, Clots on contact with minute amounts of endotoxin, Screen batches of drugs and vaccines, If done carefully and correctly, animal won't die.

Phylum Echinodermata

• Sea stars, sea urchins, sea lilies
• Derived radial symmetry as an adult, bilateral as a larvae, Lack head, oral/aboral surfaces, No dorsal/ventral sides; anterior/posterior ends.
• Triploblastic, deuterostome
• Light-sensing organs on tips of legs Exclusively marine → water vascular system.
• Locomotion → tube feet . Respiration

Marine Organisms

• Madreporite pulls water through → water flows into ring canal → leads off of the radial canal out into each arm → ampullae extend/retract podia based by hydraulic pressure.
• CaCo3 ossicles as endoskeleton.
• Microscopic/separate/fused as test.
• Sea urchins and sand dollars fuse, sea cucumber microscopic, and sea star seperate.
• Mutable collagenous tissue - ligaments normally “locked" (rigid), but can be "unlocked" (loosened) Catch collagen tissue reacts to electrical currents by not expending energy → can be used for defense and energy.

Classes

• Class Holothuroidea - sea cucumbers -Deposit feeders - feed on sediments by lying out tentacles and waiting for particles to fall or whipping particles around, Microscopic skeletal structure, Hold any body position.
• Class Crinoidea - sea lilies/feather stars, Mouth faces up Mobile → suspension feeders
• Class Ophiuroidea - brittle stars, Legs break easily → used for locomotion Suspension feed on small particles Class Asteroidea - sea stars/starfish Varied in leg size, symmetry, shape, Carnivores - feed on bivalves or other invertebrates, Those living in rocky shores pull mussel and lock their arms to use the barnacles energy to close but not the sea stars

Marine Animals

• Sea star flips stomach inside out to digest (even digests shells!), Tube feet for locomotion Class Echinoidea (sand dollars, sea urchins), Primarily herbivore (sand dollars suspension feed from holes in body), Tube feet entirely for locomotion, Regeneration - regrow lost/damaged body parts, Some species reproduce asexually by fragmentation , Defense mechanism .

Phylum Chordata

• Invert groups, Bilateral, triploblastic, deuterostome, Needs at least 1 part in life stage: Dorsal hollow nerve cord - runs along body, Notochord - runs along body, Postanal tail - separate piece behind the posterior end Pharyngeal slits - feeding/respiration located in the pharynx, Subphylum Cephalochordata - lancelet , All 4 chordate characteristics simultaneously Internal filter feeding on gill slits , Few cm length
• Minimal development of some organ systems - no respiratory system or heart , Subphylum Tunicata. Tunic - external covering of amorphous cellulose Filter-feed , Salps and Larvaceans . Class Ascidiacea, Solitary or colonial , Mobile larvae, sessile adult Exclusively marine, Sexual reproduction - brooding, broadcast spawning, tadpole larvae

Nekton

• Organisms in water column swimming strongly enough to move counter to modest water currents , Most vertebrates; some invertebrates like Giant deep sea pacific squid (>10m)

Marine Adaptations

• Similar environmental conditions as plankton 3-D environment currents/water movement . Nowhere to hide , Patchy food, ecological influence on marine communities with food cycling , Adaptations , Avoid sinking, Swim bladders, air filled bladders . Retention of fats and oils → blubber, fatty liver, Hydrodynamics (lifting surfaces) , Rigid pectoral fins , Heterocercal tail - top tail half larger than bottom half.

Strategies of Marine Life

• Streamlining to release drag, Swimming less costly than running or flying due to reduced gravity, Need to reduce drag, Sphere head minimizes SA + long cylinder body minimizes frontal SA = streamlining (form minimizes turbulence) Defenses, Schooling, Well-coordinated unit of many individuals that lack a leader, Can be made of multiple spp., Reasons, predation protection increases prey success, Hydrodynamic efficiency , Maintaining coordination .

Adaptations

• Vision, Sound, Lateral line - near and far fields of sound, Smell, countershading, Hide from predators/prey, May be more than 1 mechanism (flattening), Backlit camouflage , Ex - penguins, Darker on top view of org. than bottom view , Catching prey . Highly developed senses - sight, smell, sound, Neuromasts - in lateral line that sense near-field sound Echolocation for sound.
• Electroreceptors and lateral line canal Highly developed NS - brain

Vertebrates

• Notochord → vertebrae, Skull, Brain organized into regions, Presence of myomeres - segmented, skeletal muscles (controlled, efficient movement). Osmoregulation and homeostasis, Excretory systems - solutes and water Fish ,
• Class Agnatha - jawless fish, 90 spp. Known, No paired fins, No scales , Cartilaginous skeleton - retain notochord and rudimentary vertebrae No jaws, Oral discs with large # of teeth, Teeth can wear away with food, Hagfish, Slime! Choke animals to eat them Scavengers, some carnivory.

Sea Lampreys

• Anadromous - live in ocean, reproduce in freshwater , Parasitic/hematophagy Scrape a hole through fish skins to steal nutrients and juices , Negative effects on commercial fishes .

Marine Classes

• Class Chondrichthyes - cartilaginous fish, Around 1450 spp, Paired fins, Heterocercal tail (caudal), Biting jaw with teeth , Placoid scales Cartilaginous skeleton Largest fish - adult body length 20cm -15+ m, Sharks . Around 350 spp Elongated, streamlined bodies, Often nektonic - nurse shark demersal. Carnivores - fish, mammals, molluscs, crustaceans, echinoderms, Filter feeders - whale shark

Marine Characteristics

• Rayes and skates , Around 500 spp, Depressed, flattened bodies Most demersal, Carnivores - fish, molluscs Filter feeders - manta ray, chimaeras/ratfishes , Around 30 spp .
• deep sea, demersal, Lees known because of depth , Carnivores - fish, crustaceans, molluscs, worms, echinoderms, Differences - no scales on skin, lack shark replaceable teeth

Bony Fish

• Class Osteichthyes - bony fish, Around 13,300 spp Paired fins, jaws with teeth, Calcified, bony skeleton Overlapping scales, Gill cover - operculum, Swim bladder.
• Homocercal tail, Smaller than chondrichthyes because bones allowing for smaller body sizes, Subclass Sarcopterygii - lobe-finned fishes, Coelacanths.
• 2 extant spp , First known from fossils , Thought extinct until 1938 Subclass Actinopterygii - ray-finned fishes, Swim bladders + bony skeleton = diversification of body parts Body shape related to lifestyle

Marine Order

• Ex - lionfish, grouper, seahorse, butterfly fish Trade Offs , Cruising - (tuna)High, stiff streamline , Lunate tail Maneuver - (butterfly fish), Lateral, flexible bodies Broad tail

Marine Traits

• Rapid acceleration (barracuda), Elongated, not streamlined body, Strong, thick caudal tail