Graduate Student Presentations Flashcards
Where would you most likely find a kelp forest?
Cold and shallow waters
What type of habitat would a fish with a large body size choose?
Low density of vegetation
What type of habitat would a fish with a small body size choose?
High density of vegetation or coverage
In what ways would kelpfish use structured habitats?
To minimize their predation risk, increase their food intake, and growth
Explain how climate change can impact the kelp forests?
Rising temperatures are causing range expansion of tropical grazing species like the Sea Urchins. This increase in urchin grazing prevents the regrowth of kelp forests even though kelp in general is fairly fast growing.
Based on the results of the study, Regressive evolution: Ontogeny and genetics of cavefish eye
rudimentation, how many stages are there in fish eye development?
4
What is the difference between terrestrial vertebrate eyes and fish eyes?
Fish eyes have a more spherical lens than terrestrial vertebrates.
Fish move their lens closer/further away from the retina in order to focus , while birds
and mammals change the shape of the lens for focus light on the retina.
In what stage of cave fish eye development do apoptotic centers appear and how do they affect
the fish eye growth?
Stage 2, they contribute to a halt in eye development.
How did the Molino cavefish differ from the other cavefish populations?
The Molino cavefish visual cells develop and are organized in the outer segment, but
then are secondarily reduced in a later stage of development.
In the study, Regressive evolution: Ontogeny and genetics of cavefish eye rudimentation, what were the two hypotheses about cavefish eye rudimentary? What did the results indicate about the ontogeny of cavefish eye rudimentary? Which hypothesis did the results support? Do you think the data was reliable or significant enough for the authors to make their conclusions?
The first states
that after lens induction by the primordial eye cup, the lens plays the role of a central regulator of eye and retina regression. The second says the retina itself is an independent unit of eye development.
Eye development in the cave fish is not linear and can be divided in four stages with specific histological and growth characteristics.
In Cave fish, the lens does not properly differentiate, and the regressive process of retina
is interrupted intermittently. In the Molino fish, the visual cells develop and are organized in the
outer segment, but then are secondarily reduced in a later stage of development. Thus, further
proving the retina and lens are independent units in eye development.
Why are anadromous brook trout uncommon south of Maine, USA?
Ocean temperatures are near or exceeding brook trout’s thermal threshold.
Which of the following anadromous species are native to the eastern United States?
Atlantic salmon (Salmo salar)
Why are fish kill events so catastrophic to anadromous brook char populations on Prince Edward Island, Canada?
Local agricultural practices include the spreading of pesticides/herbicides during brook char migration/spawning
Why have exotic salmonids been introduced to waters in the eastern united States?
To diversify sport fisheries
Discuss the difficulties in the management and protection of anadromous fishes
Anadromy allows fishes to cross a multitude of ecosystem managed by different governmental agencies: state, territory, and national borders. It would take communication and coordination between NOAA, FWS, USGS, USDA, NPS and others to fully regulate and protect these fish. The web of agencies needed to protect the fish complicates everything because of anadromy.
