On the other hand, the low total abundance of individuals found in this study can be explained by the presence of potential predators of oligochaetes, such as odonatan and megalopteran
The eastern dobsonfly (Corydalus cornutus), with a wingspan of almost 6 inches, is the largest Megalopteran
in the northeast.
Among invertebrates, megalopteran larvae (Corydalus sp.) were present in 31.6% of the samples containing invertebrate remains.
In the present study, however, arthropods may be an important component in the otter diet once insects not associated to fish remains were found in six samples, one of those with only megalopteran Corydalus sp.
We collected 22 taxa (10 species & 12 taxa identified to genus or family) of invertebrates, including one isopod, 1 decapod, 4 pelecypods, 1 gastropod, 1 leech, 1 annelid, I triclad, 5 dipterans, 2 odonates, 2 coleopterans, 2 hemipterans, and 1 megalopteran
. The only fish collected were Green Sunfish (Lepomis cyanellus) from the stream.
Density dependent shifts in attachment site by the ectosymbiotic chironomid Nanocladius asiaticus on its megalopteran host Protohermes grandis.
Other commonly reported insect hosts include megalopterans. Almost two-thirds of the hellgrammites (Corydalus cornutus) from a Tennessee stream carried chironomids (Furnish et al., 1981).
Sculpin from 15% embedded streams consumed ephemeropterans and megalopterans
. Megaloptera were one of the least abundant groups present.
Megalopterans are among the most primitive of winged insects in the world (Aspock et al., 2001) and include two families: Corydalidae (dobsonflies and fishflies) and Sialidae (alderflies).
However, because megalopterans commonly exhibit some degree of phenotypic (including genitalia) plasticity (Bowles and Mathis, 1992), it is not clear whether these specimens represent true hybrids or intraspecific variants.
Masses of taxa with relatively large individuals such as odonates, caddisflies, and megalopterans
were estimated by determining allometric relationships (from [greater than or equal to] individuals) of linear body dimensions such as head capsule widths or body length to dry mass specific for these lakes.
1b) consisting of benthivorous perch (Perca fluviatilis = TC), larval megalopterans
(Sialis lutaria) and odonates (both lumped into one component = IC), and larval chironomids (= R, which consisted of a variety of noncarnivorous genera).