Fungal and Lichen Diversity

General characteristics of fungi:

• Filamentous

• Spore-producing

• Heterotrophic

• Unicellular or multicellular

• Possess a chitin cell wall, store energy in the form of glycogen

• Mostly decomposers, but some are parasitic or mutualistic

• Release digestive enzymes onto a food source to dissolve it

• Hyphae — numerous small filaments that compose multicellular fungi

• Mycelium — grouped together mass of hyphae

• Septa — cross walls of hyphae that allow structures like ribosomes and mitochondria to pass through

• Rhizoids — modified hyphae that anchor fungi into substrate

Basidiomycota

• Mushrooms, shelf fungi, and puffballs

• Produce basidiospores (similar to the ascus)

• Some can be edible

Chytridiomycota

• Most ancient group of fungi

• Most chytrids are either aquatic decomposers feeding on dead material or parasites living on water molds, insects, or snakes

• Cell walls composed of chitin

• Have flagellated spores and gametes

• Most are unicellular

• Can be found outside of water in moist environments

Ascomycoda

• Largest and most diverse phylum of fungi

• Lives pretty much anywhere

• Can be unicellular or multicellular

• Gets their name from the ascus, a large saclike cell responsible for producing reproductive ascospores

• Fruiting bodies are called ascocarps

Zygomycota:

• Bread molds

• Reproduce via conjugation

• The hyphae lack septa and are called coenocytic

• Three types of hyphae: rhizoids anchor hyphae, stolons grow horizontally on the surface

• Asexual life cycle: rhizoids make sporangiophores, which make two progametangia that meet and form a zygosporangium, which releases meiospores

Lichen

• Symbionts consisting of a green algae or cyanobacterium

• Algal cells or cyanobacteria are thought to provide food for both symbionts through photosynthesis and the ascomycete retains water and minerals, anchors the organism, and protects the algae

• Nearly 20,000 species

• Body is called a thallus and mainly reproduce asexually

• Typically live on trees, rocks, and human structures. But can also live in crazy conditions

• Associated with making dyes, litmus paper, bandages, and antibiotics. They help build soil, provide food and habitat, some fix nitrogen and are indicators of air pollution.

• Three types:
  Crustose: form brightly colored patches or crusts on rock or tree bark
  Foliose: appear to have leaf like thalli that overlap, forming a scaly, lobed body. Found on tree bark and human made structures
  Fruticose: appear shrub-like or hanging mosslike on trees. Thalli are highly branched or cylindrical.

Animal Diversity I

Phylum Porifera

• Consist of sponges

• Believed to have evolved from flagellated aquatic eukaryotes known as choanoflagellates

• Adults are sessile, they don’t move

• Larvae do move though

• Outer structure consists of fibrous collagen and calcareous or siliceous crystalline spicules and spongin, a collagenous protein in many species

Sponge anatomy:

• Bodies are organized around a system of water canals and chambers

• Ostia — openings that allow water into the sponges interior

• Spongocoel — the central cavity of a sponge

• Choanocytes — flagellated collar like cells that line the spongocoel

• Gemmules — buds sponges form to reproduce asexually

• Osculum — the opening in the sponge that water exits from

• Mesohyl — a gelatinous matrix that the cells of sponges are arranged in

• Amoebocytes — cells that move around the mesohyl and absorb, digest, and transport food

Sponge canal system:

• Asconoid — sponges are small and tube shaped, water enters through tiny ostia and exits through a large osculum

• Synconoid — have a more complex canal system, with choanocytes in numerous radial canals that empty into the spongocoel, then exits through the osculum

• Leuconoid — sponges form large masses, with clusters of flagellated chambers received water from the canals, with discharged water leaving through the excurrent canals and osculum

Sponge Classification:

• Class Calcarea: small marine sponges with spicules composed of calcium carbonate. May be vase-shaped, brightly colored, can have any body form

• Class Demospongiae: largest class of sponges, often brilliantly colored. THey have siliceous spicules sometimes bound together by spongin and have leuconoid canal systems. Some members live in freshwater habitats.

• Class Hexactinellida: known as glass sponges because of their six rayed siliceous spicules that form a glass-like lattice. These sponges are primary deep-water marine forms with cylindrical or funnel-shaped bodies. They can have simple syconoid or leuconoid flagellated chambers.

Phylum Cnidaria

• Named after the cnidoblasts which contain stinging cells or nematocysts used for food gathering and defense

• Two main body forms:

  Medusa — like jellyfish

  Polyp — like coral

• Larvae called planula

• Exhibit radial symmetry and are diploblastic

• Reproduction can be asexual via budding, or sexual

Cnidaria Classification:

• Class Hydrozoa — mostly marine, dominant polyp form

• Class Scyphzoa — solitary medusas

• Class Cubozoa — have a prominent Medusa form

• Class Anthozoa — colonial or solitary polyps

Phylum Ctenophora

• Solitary, harmless, exclusively marine, jellyfish like animals

• Also known as sea walnuts/sea gooseberries

• Very small phylum

• Exist as a medusa only

• Live in warm water worldwide

• Have adhesive cells called colloblasts to capture food

• Do not possess nematocysts, meaning they can’t sting you

• Swim by rows of fused cilia called comb plates

• Most are monoecious, reproduce only sexually, many are bioluminescent

Phylum Platyhelminthes

• Dorsoventrally flattened, ribbonlike bodies

• Bilaterally symmetrical, triploblastic acoelomates with a large surface area

• Many species are monoecious and practice cross-fertilization

• Gas exchange occurs via diffusion

• Their digestive system is incomplete, only one hole

• They exhibit cephalization: a pair of cerebral ganglia receiving sensory information from the environment

• Eye spots are present in some species. Each ganglion is connected to a nerve cord that runs the length of the body

Platyhelminthes Classification

• Class Turbellaria: free-living flatworms

• Class Cestoda: parasitic tapeworms

• Trematoda: parasitic flukes. Largest class

• Monogenea: ectoparasitic flatworms usually found on the skin and gills of fishes

Phylum Rotifera

• Pseudocoelomates that live in aquatic environments

• Possess a crown of cilia on their head, known as a corona, which is used for feeding and movement

• Have a foot that contains adhesive glands that open to the exterior via spurs

• Have a unique pharyngeal apparatus called the mastax, which possesses grinding jaws used for grinding up algae and smaller invertebrates

• They have a complete digestive system

• Rotifers lack a circulatory system and respire through their body surface

• Rotifers are dioecious, with generally larger females than males

• To cope with environmental stress, rotifers can enter an arrested state of activity called cryptobiosis, which can last up to 4 years

Phylum Mollusca

• Super diverse but share a bilaterally symmetrical body plan

• Foot - thick muscle used for digging, grasping, and movement

• Visceral mass - contains the digestive, respiratory, circulatory, and reproductive systems

• Mantle - a sheath of skin extending from the visceral mass and hanging down each side of the body, protecting the soft parts of the organism

• Shell - composed of calcium carbonate and a protein matrix

• Radula - protrusible, tonguelike organ used for rasping

• Terrestrial snails have lungs for gas exchange

Classification of Mollusks

• Polyplacophora — chitons

• Monoplacophora — organisms with a cap-like shell

• Gastropoda — snails, abalone, whelks, limpets, slugs and nudibranchs

• Cephalopoda — octopi, squid, cuttlefish, nautiluses, and fossil ammonites

• Bivalvia — calms, oysters, mussels, scallops

• Scaphopoda — tusk shells

Bivalve Characteristics

• Two separate shells joined by a ligament called the hinge

• The umbo is the oldest part of the shell. It looks like a large hump on the top of the shell

• Powerful adductor muscles hold the valves of the shell together. Most bivalves have a posterior and an anterior adductor muscle. Scallops just have one

• They lack a head and radula

• Bivalves live in marine as well as freshwater environments

• Most are filter feeders

• They take in water and nutrients in the incurrent siphon and eliminate by the excurrent siphon

• Gas exchange occurs through the mantle and gills

Animal Diversity II

Phylum Chordata

• Fundamental characteristics:
  A notochord, dorsal nerve chord, pharyngeal pouches, and a postanal tail.

• These can exist throughout life or only during embryological development

• Additional traits:
  Bilateral symmetry
  Segmentation
  Radial cleavage
  Triploblastic
  Deuterostomes

Subphylum Vertebrata

• All members have a skull

• Have a neural crest, group of embryonic cells that form cranium, jaws, teeth, and some nerves

• Metabolically more active, more complex muscular system

• Have a multi-chambered heart and hemoglobin

• Specialized organs, like liver and kidneys

Phylum Echinodermata

• Sea stars, feather stars, urchins, and sea cucumbers

• Pentamerous (5-pointed) radial symmetry

• Body wall consists of small calcareous ossicles that include surface spines

• The spines can have pedicellariae that discharge organisms from gettin on them

• Possess a unique water vascular system that allows them to be moving, feeding, sensing, and gas exchangin

• Sea stars have tube feet

• Lack head, brain, and segmentation

• Dioecious, most have complete digestive system

• Larva are bilaterally symmetrical, called bipinaria

• Can lose a limb to avoid being caught by predators, known as autonomy

Subphylum Cephalochordata

• Sea lancets

• Inhabit sandy coastal waters, bury their posterior end into the sand and stick their anterior end above the sand to filter feed

• Notochord and nerve chord persist

• Complex, closed circulatory system of gas exchange

• Have segmented repeating muscle units called myomeres

• Water enters the mouth and passes to the endostyle, where it’s trapped by mucus and moved to the hepatic cecum where it’s digested

Phylum Arthropoda

• A chitinous exoskeleton — some are soft and some are hard

• Bilateral symmetry

• Head, thorax, and abdomen

• Possess a variety of sense organs, such as compound eyes and antennae

• Coelomates

• Complete digestive system with foregut, midgut, and hindgut

• Have efficient tracheae (airtubes) that bring oxygen directly to the cells

• Open circulatory system

• Many undergo metamorphic changes

• Females are usually oviparous (egg-laying)