Marine Bio Exam 2 Flashcards

syn(together)gamy(gamete)

The process of creating babies with 2 different gametes, scientific term for fertilization, the fusion of 2 gametes (the act of sex). The bringing together of two gametes to create a zygote

-Two main types of syngamy we discuss in class are internal and external fertilization (You can have internal fertilization and no parental care and vice versa, OR external fertilization with a large amount of parental care)

*Better term to use than fertilization bc it doesn’t assume oogamy; doesn’t assume that there can only be an active sperm and passive egg *

• For humans, sperm is considered active and the egg passive, this is not always true for marine organisms

Internal fertilization ( type of syngamy)

A reproductive process where fertilization occurs inside the female's body, allowing for greater protection of the developing embryo. happens within the LARGE gamete producer's body.

What are the 3 main methods of internal fertilization?

direct sperm transfer, Indirect sperm transfer, and Spermcasting

Direct sperm transfer

The method where sperm is transferred DIRECTLY from the male to the female during mating, typically involving copulation.

• The case for many gastropods – snails and slugs , barnacles

• This method allows for immediate fertilization, ensuring that the sperm reaches the egg without delay, enhancing reproductive success.

Indirect sperm transfer

A reproductive method where sperm is released into the environment and must find the egg. This approach can be seen in certain fish and amphibians.

An important way of doing this is through the use of sperm packets called (“spermatophores”). These sperm packets are given to egg producers: Cuddlefish, squid, crabs, and encephala pods do this.

Sperm casting

A reproductive strategy where males release sperm into the water column, allowing it to drift and potentially fertilize eggs released by females.

*A lot riskier!* Involves precise timing and coordinated release for increased success of fertilization!

some barnacles, bivalves, sponges, & many corals do this.

External fertilization (type of syngamy)

A reproductive process where fertilization occurs outside the female's body, typically in aquatic environments, allowing sperm and eggs to meet in the water.

What are the two main types of external fertilization?

Broadcast spawning &  Substrate spawning

Broadcast Spawning

A reproductive strategy where organisms release a large number of eggs and sperm into the water column simultaneously, INCREASING chances of fertilization.

gametes are released into the environment and must find each other (common among corals) the gametes are buoyant and float to the surface.

Sea urchins and seaweeds also do this.

Why are buoyant gametes needed?

It is an adaptive stratetgy! why? Well B/c if the gametes are randomly dispersed they wont be concentrated(close together)enough decreasing their chances of fertilization, but if they sit on top of the water’s surface, they will be closer together and less diluted. This makes it easier for gametes to find each other

coral gametes do this by being buoyant

Seaweed gametes do this by swimming towards light

Sea Urchin Broadcast Spawning

• Sea urchin gametes are negatively buoyant→ they stay near the bottom and therefore which also prevents dilution

• Being negatively buoyant is an evolutionary adaptation, it is better to be dispersed on the flat surface of the benthos (bottom seafloor) than to be separated, makes it easier for them to connect

• Echinoderms, and many sessile mollusks do this

Substrate Spawning

• large gamete producer releases gametes onto substrate (eggs/female gametes) and small gamete producer releases gametes on top of them(sperm/male gametes)

• many fish do this (think Finding nemo scene when all the eggs got crushed up)

• Substrate: In marine biology, substrate refers to the material at the bottom of marine habitats. This material can be dirt, rocks, sand, or gravel. The substrate serves as a dwelling place or the source of food for some microorganisms.

  
  

Which reproduction process takes the most energy? Why?

Internal Fertilization!

• much harder bc u have to find and address your mate which requires active movement and specialized organs like large penis, sperm packets, etc

• Also the eggs/babies must grow inside the egg producer VS. External syngamy, the investment in the offspring is complete after gametes are released – parental care is done 

What are the post-internal fertilization processes?

1. Ovi(egg)parity(birth) (n); (Oviparous adj)

2.Viv(live)iparity (n) (viviparous adj):

3.Oviviviparity(ovoviviparous)

What is Oviparity?

-they lay eggs, embryo develops in an egg OUTSIDE a parent body, nutrients come from the egg

-LEAST energy needed, zygote completely reliant on egg alone, parents can guard it but overall less energy)

-Oviparous parents either stay and protect their eggs or don’t 

-Examples: Littorina littorea (common periwinkle, invasive species) &  L. obtusata (smooth periwinkle)

What is Viviparity?

• live birth ONLY mammals do this, embryo develops inside a parent taking nutrients directly from that parent (TAKES THE MOST WORK/ENERGY bc it takes directly from the parent, the amount of energy it will take is not set in stone)

What is Oviviviparity

•  egg live birth, embryo develops inside an egg inside a parents body, nutrients comes from egg

• Examples: (sharks) & L. saxtallis (rough periwinkle)

How do smooth periwinkles (L. obtusata) carry out oviparity?

•  L. obtusata (smooth periwinkle): after release they attach their eggs to the substrate(rocks, undersides of seaweeds, this act takes more physical effort, the gluing, finding a substrate etc. They also don’t guard their eggs, glued to a rock for protection, less likely to be eaten or damaged, glued to a rock means = in a good habitat with good food)

How do Littorina littorea (common periwinkle, invasive species) carry out oviparity?

-the egg producers release fertilized eggs into the water column having a similar outcome to broadcast spawning. Releasing them into the water allows them to spread around, if something comes to kill the offspring some will be able to get away thru this dispersal,

-if eggs are placed on a rock– as other organisms do, the offspring runs the risk of ALL of them getting eaten,

-also Littorina Littorea’s method prevents competition/pressure to survive next to other offspring that are eating supply nearby as well

What are the 3 post-hatching of egg offspring categories?

-Direct developers

-Planktotrophic Larvae

-Lecithtrophic larvae

What are direct developers?

no larval phase(can be brooded or not)

• EX: as soon as they exit the egg they look like snails, fully developed in egg, may take time

What are planktotrophic larvae?

• larvae of plankton, small but can feed, can spend more time in the water column bc they have to find food to eat, also have to swim around to find a good spot to eat

• downside: they have to find their own food

What are Lecithotrophic larvae?

• get all of their nutrients from their yolk sack, hatch bigger, larger investment for parents, undergo quick metamorphosis, don’t have to go far, easier chances to find a place to settle because they’ve never had to leave the location where their eggs were dropped.

• Examples of lecithotrophic larvae (sea urchins - Echinoidea, sea cucumbers - Holothuroidea, Starfishes - Aseroidea, ribbon worms - Nemertini, segmented worms - Polychaeta)

What is a Trophic Pyramid?

-A trophic pyramid, also known as an energy pyramid or ecological pyramid, visually represents the flow of energy and biomass through different trophic levels in an ecosystem, with producers at the base and consumers at higher levels. 

What trophic levels take the most and least amount of energy?

• expect most energy and biomass at the autotroph level - primary producers, algae as well, they take the energy from the sun and turn it into energy the rest of the organisms can use

• The next most abundant trophic level(guild) would be herbivores, primary predators, and secondary consumers/producers

Autotroph?

Auto(troph-eating): self-feeds by using the sun

How do scavengers and deposit feeders get their food?

They are organisms that sift through grains of sand and decaying organisms to get the last of their nutrients out of them

Primary producers

Marine primary producers are organisms that produce their own food using sunlight (through photosynthesis) or chemicals (through chemosynthesis) and form the foundation of marine food webs.

Seaweeds and color pigments

Seaweeds and plants have lots of different pigments and what pigments they use is determined by how deep they can live underwater.

Red Seaweed

• Red seaweed was the first to evolve and use a lot of pigment in the phycocyanin and phycoerythrin ( absorbing all of the green and yellow light to reflect RED)

• No other seaweeds do, they can live in much further depths than other seaweeds bc of this.

• Red seaweeds have the most variety of colors (pinkish red seaweed) - Corallina officinalis

• Red algae use SOME chlorophyll A pigment

Brown Seaweeds

All kelps are brown seaweeds (youngest of the three seaweed groups

• The most common brown seaweed: Ascophyllum nodosum 

• Brown algae uses Chlorophyll A, B , and carotenoids for its pigment

Green Seaweeds

GREEN seaweeds are what ALL land plants evolved from, only a couple cells thick

• Green algae are only using pigments chlorophyll A and B, they are collecting the colors that they’re over (insert diagram from slides)

• Chlorophyll A gets energy from red light , absorbs purple and red light and reflects back green which is why chlorophyll looks green