from wikipedia on Species.
http://en.wikipedia.org/wiki/Species
Abbreviation
Books and articles sometimes intentionally do not identify species fully and use the abbreviation "sp." in the singular or "spp." in the plural in place of the specific epithet: for example, Canis sp. This commonly occurs in the following types of situation:
The authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong. This is particularly common in paleontology.
The authors use "spp." as a short way of saying that something applies to many species within a genus, but do not wish to say that it applies to all species within that genus. If scientists mean that something applies to all species with a genus, they use the genus name without the specific epithet.
In books and articles that use the genus and species names are usually printed in italics. If using "sp." and "spp.," these should not be italicized.
Tropheus species
Tropheus Moorii - (species Black, species Red, non-rainbow types, sp.ikola)
Tropheus Kasabae - (southern rainbow types only)
Tropheus brichardi - (east and west side of the lake most abundant, sp.mpimbwe)
Tropheus Duboisi - (found in Northern half)
Tropheus Polli - (East Coast at Bulu Point/Karilani Island area only)
Tropheus Annectens - (East Coast South of Bulu Point, and Central West Coast.)