Lab 4 Study Notes Flashcards
Last phylum in Clade lophotrochozoa?
Mollusca
Second phylum in Clade ecdysozoa?
Arthropoda
What type of development do the invertebrates studied have so far?
Protosome type development
Using the proposed molecular phylogeny, what clade is phylum mollusca in?
Lophotrochozoa
Using traditional morphology based phylogeny, what phyla is mollusca grouped with?
Annelida and Arthropoda
How many classes are in phylum mollusca?
8 classes
What 3 classes of mollusca are studied in lab 4?
Class gastropoda, bivalvia, and cephalopoda
What 4 characteristic features do the animals in mollusca share?
1) a hard external shell 2) a shell-secreting structure called the mantle 3) a visceral mass containing most of the organs 4) a muscular foot used for locomotion
Why is a mussel a bivalve?
Because its shell is made of two parts
Where are mussels found?
Both marine and freshwater habitats but all are aquatic
All bivalves are filter-feeders. What does this mean?
It means they draw in and then expel water, and their morphology reflects specialization for this kind of lifestyle
What are the types of specialization that bivalves do?
1) some are sedentary and anchor themselves in place 2) others can use their muscular foot to slowly locomote
What bivalve was dissected in lab 4?
A mussel
What is the umbo?
It is the bump that is the oldest part of the shell. A mussel’s valves are held together by a hinge near the umbo.
How is a wooden peg used by a mussel?
It is used to keep the shell halves apart but it is necessary to cut through the anterior and posterior adductor muscles before opening it
When the mussel has been opened, what is the flap of tissue first observed?
It is called the mantle and secretes the shell. (If debris gets stuck between the mantle and shell, the mantle will secrete layers around it.)
What are the two mantle flaps observed at one end of the mussel?
These flaps form the excurrent and incurrent siphons
A = excurrent siphon B= incurrent siphon
In a mussel, what has an intricately folded appearence?
The gills and they function in respiration
Tell me about the heart of a mussel. Where is it located? What are it’s characteristics?
It is located in the pericardial cavity which is a greatly reduced true coelom
What does the mussel’s visceral mass contain?
It contains organs like the gonads, digestive gland, intestine and stomach (this all makes up clam chowder! Ewww…)
Which class of mollusca is the largest and most diverse?
Class gastropoda
What kinds of animals does class gastropoda include?
Snails, slugs, whelks, and limpets.
Where can you find the class gastropoda?
In freshwater, marine and terrestrial habitats
What characterizes class gastropoda?
1)Most members have a long flat foot used for locomotion 2) distinct head with eyes and tentacles 3) visceral mass is located dorsally and housed within a spiral shell
The spires of a gastropods shell may show right or left side coiling. What’s this called?
This is called dextral and sinister coiling respectively
How do gastropods eat?
They are herbivores that use their radula to scrape vegetation in their mouth
What gastropods were examined in lab 4?
2 different species of live aquatic pond snails
What sets cephalopods apart from other mollusks?
1) they either have a greatly reduced and internalized shell or no shell at all 2) rather than a large muscular foot, it is differentiated into arms and tentacles that aid in grasping prey 3) they have a closed circulatory system
Nervous system of cephalopods?
Is extremely sophisticated and they are capable of learning complex tasks
Where do cephalopods live?
They are all marine and make for good predators in their habitats
What cephalopod was observed in lab 4?
A squid
How do the tentacles and arms of a squid differ in size and morphology?
There are many arms which are small with suckers all around while the there are 2 tentacles with suckers only at the ends. The tentacles are also much longer than the arms
What does the siphon on the posterior surface of a squid do?
It is where the squid expels water after taking it into the mantle cavity. Squids use this to propel themselves!!
Number 2 = siphon
What is the edge of the mantle beside the eye known as?
Known as the collar
What is the pen of a squid?
A projection of the mantle with a hard structure inside, on the anterior side of a squid
Where is the radula in a squid found?
It is found inside the mouth
Which animal phylum contains the most animals and individuals?
The arthropods
Where are arthropods found?
In almost any environment. From the bottom of the ocean to deserts to mountain tops
How do arthropods feed?
They can be filter feeders, herbivores, carnivores and parasites
What sets the arthropods apart?
1) have a cuticle that is more elaborate and forms a tough exoskeleton that is shed as the animal grows 2) they have external segmentation (like annelids) but this is not as obvious in modern arthropods since segments become fused into specialized regions called tagmata
The four living subphyla of Arthropoda?
1) Chelicerata 2) Myriapoda 3) Crustacea 4) Hexapoda
How do Chelicerata feed?
They have distinctive pincer-like appendages called chelicerae and also pedipalps that aid in feeding
How can the Chelicerata be identified?
1) distinctive mouthparts 2) presence of 8 walking legs 3) have simple eyes
Animals in Chelicerata?
Horseshoe crabs, spiders, ticks, mites
Spiders?
1) All carnivorous 2) 8 walking legs 3) Chelicerae and pedipalp 4) 2 tagmata 5) Three pairs of spinnerets on posterior end which helps spiders spin webs from their silk glands
Two most well known groups in Myriapoda?
Millipedes and centipedes
How do Myriapoda feed?
With the chewing mouthparts, maxillae and mandibles (not related but Myriapoda can also have antennae)
How many legs on each segment and how many tagmata in a centipede?
1) 2 legs on each segment 2) many tagmata! (I think!)
Characteristics of Crustacea?
1) in larger species, the exoskeleton is hardened on the dorsal side to form a carapace 2) have mandible and maxillae for feeding 3) antennae may be present but doesn’t have to
Members of crustaceans?
Crabs, shrimps, lobsters, copepods (most marine)
Crustacean dissected in lab 4?
A crayfish
What is the most diverse and largest subphylum of Arthropoda?
Hexapoda and they can be found in almost any habitat! Many capable of powered flight and most have two pairs of wings Many also undergo metamorphosis
What Hexapoda was dissected in lab 4?
A grasshopper
What are the small dots found along the side of a grasshopper?
Spiracles and they’re the opening to the trachae These flexible air tubes connect to air sacs and have very fine branchings to deliver oxygen directly to cells
What is the hemocoel?
Arthropods are true coelomates but the space between the body wall and digestive tract is the hemocoel. This is cuz it’s filled with a colourless circulatory fluid called hemolymph This fluid is pumped by a long tubular heart
What runs along with the body of a grasshopper?
The ventral nerve cord The expanded regions (ganglia) of the nerve cord can be observed in each body segment
Fruit fly anatomy?
3 tagmata present in fruit fly Compound eyes
Two types of metamorphoses?
Complete and incomplete
Clade?
Phylum ?
Subphylum?
Clade = ecdysozoa Phylum = arthropoda Subphylum = chelicerata
How is the squid exchanging oxygen ?
Detect squid radula
This is what it is supposed to look like.
Clade ?
Phylum?
Class?
Clade= lophotrochozoa
Mollusca
Class = cephalopoda
Clade ?
Phylum ?
Class ?
Clade = lophotrochozoa Phylum = Mollusca Class = Gastropoda
Clade ?
Phylum?
class ?
Lophotrochozoa
Mollusca
Class = bivalvia
Clade?
Phylum?
subphylum?
Ecdysozoa
Phylum = Arthropoda
Subphylum = myriapoda
Clade
Phylum
Subphylum
Ecdysozoa
phylum = Arthropoda
subphylum = Hexapoda
Clade
Phylum
subphylum ?
Clade = Ecdysozoa Phylum = Arthropoda Subphylum = hexapoda
NAME ?
Snail radula
Clade
Phylum?
Subphylum?
Ecdysozoa
Arthropoda
Crustacea
