Haliotis
Abalone

Heterotrophic
Any organism that is not autotropic: a secondary producer.
Utilizes the organic material produced
by an autotrophic organism.

Holopplankton
Organisms that exist only as planktonic forms.

Homology
Correspondence in stucture or different organ-isms that seem
to have the same evolutionary
origin; (for example, the leg of a horse and the leg of a cow).

Heteromorphic
Where sporophyte and gametophyte appear different.

Hold fast
The part of an algae that grips the substrate and holds the
plant fast.

Hermaphroditic
Having both male and female gonads.

Hydrozoa
The various hydroid forms belong to this class.

Hemocoel
Spaces in the body through which blood flows instead of in
blood vessels.

Holothuroidea
Class containing the sea cucumbers.

Haploid
Chromosomes that are single not paired. 1N.

Histology
The study of tissues.

Hadopelagic zone
The area below 6,000 meters deep.