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Marine Diatoms

Chaetoceros sp.


This chain had at least a dozen individuals on it. This one had very distinct little dots that I'm guessing are chloroplasts. This was the most abundant genus in this sample, which makes sense as it is one of the largest genera of marine plankton. Each cell has two spines on each valve (four total per individual). I separated out different photos from this genus as I think they were different species, though I am not really positive.


A marine biologist on board skimmed some plankton using really fine mesh nets and we took a drop from that sample and placed it under a microscope. The sample was skimmed in Izhut Bay just off Afognak Island in somewhat shallow water (less than 200 feet).


Plankton from this genus can be damaging to fish, as the spines can cut up the gills of small fish, and during large blooms they can even clog up their gills. Spines also can introduce bacteria when they damage tissue and also stimulate mucus production, both of which can be damaging and sometimes even deadly to fish.

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Spotted by

Alaska, USA

Lat: 58.22, Long: -152.25

Spotted on Sep 19, 2019
Submitted on Nov 1, 2019

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