The seasonal biological surveys of 1971 / John C. Ayers, Samuel C. Mozley, John A. Stewart.

RESULTS

Appendix D contains all the species-level data from April, July and
November 1971 samples in their present state of analysis. More detailed
identification of Mollusca and exact species names for Chironomidae will be
possible after special studies. While Mysis relicta is not strictly a benthic
organism, it is collected in grab samples because of its daytime benthic occurrence. We report data on its abundance separately from other benthos at
the end of each table. All further analysis presented in this report derives
from these tables or from Part XV in this series (Mozley 1973b) and Mozley
and Garcia (1972).
New Species
The addition of new species to the register of zoobenthos near the Cook
Plant will doubtless continue for the full term of the project as taxonomic
criteria are revised or greater detail is achieved, or simply because any
ecosystem contains a large number of very rare, possibly accidental species
which gradually come to light as sampling continues. This is evident in the
additions which have been made between analysis of the July and November
surveys in 1971. A new unpublished key to aquatic oligochaetes of the Great
Lakes by K. Hiltunen (Bureau of Sport Fisheries and Wildlife, U. S. Dept. of
the Interior, Ann Arbor, Mich.) enabled us to distinguish Limnodrilus spiralis
from L. hoffmeisteri. Ophidonais serpentina and LimnodriZus udekemianus were
rare species, observed for the first time in November 1971. PiguetZlla.richiganensis was probably confused with immature Tubificidae without hair
chaetae in earlier surveys. A new type of Chironomidae larvae, Cyptochironomus sp. 4, appeared in November 1971 for the first time but was represented
by only a single individual. As mentioned in a footnote to Part XV in this
series (Mozley 1973b), the chironomid reported as Monodiamesa cfr. bathyphila
can be identified positively as Monodiamesa tubercuZata since publication of
Saether's (1973) key to the genus in North America. Review of specimens from
all surveys through 1971 showed that only this species was represented in our
collections.

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