Figure 6. Family Ameletidae - Ameletus sp. nymph

	FAMILY AMELETIDAE
TAXONOMIC CHARACTERS	Labrum without a distinct notch in the midline; mandibles rarely with tusks; maxilla with a fringed bottom edge; tarsal claws on all legs similar in structure; gills on abdominal segment 2 present; abdominal gills not forked; each gill with a sclerotized band along its outer edge; paired dorsal tubercles on abdominal segments rarely present; head and body not distinctly flattened dorso-ventrally
DISTRIBUTION IN NORTH AMERICA	In the west from southern California to northern Alaska, Yukon, and the NWT; in the east from South Carolina to Quebec; absent in the central part of the continent from the Gulf of Mexico through the Great Plains to Hudson Bay
TOTAL NUMBER OF GENERA IN N.A.	1
TOTAL NUMBER OF GENERA IN B.C.	1
TOTAL NUMBER OF SPECIES IN N.A.	32
TOTAL NUMBER OF SPECIES IN B.C.	12

	GENUS AMELETUS
TAXONOMIC CHARACTERS	Tarsal claws without denticles; gills on all abdominal segments single and oval; gills on abdominal segment 1 half as small as gills on abdominal segments 3-5; caudal filaments much shorter than abdomen, and with dark bands and intersegmental bristles along their entire length
HABITAT	Among pebbles, vegetation, or debris of small, fast-flowing streams in mountainous areas
HABIT	Swimming or clinging
FEEDING METHOD	Collecting-gathering or scraping
COMMENTS	Extremely strong swimmers; some species can be found occupying tiny rivulets
SPECIES RECORDED IN B.C. TO DATE	celer, cooki, oregonensis, pritchardi, shepherdi, similior, sparsatus*, suffusus, validus, vancouverensis, velox, vernalis

*A potentially rare and endangered species, known at present only from the South Okanagan (Scudder 1994).

Figure 7. Family Baetidae - Callibaetis sp. nymph

	FAMILY BAETIDAE
TAXONOMIC CHARACTERS	Labrum with a distinct notch in the midline; mandibles rarely with tusks; tarsal claws on all legs similar in structure; gills on abdominal segment 2 present; abdominal gills not forked, may be doubled, but never ending in a slender process; paired dorsal tubercles on abdominal segments rarely present; head and body not distinctly flattened dorso-ventrally
DISTRIBUTION IN NORTH AMERICA	Widespread
TOTAL NUMBER OF GENERA IN N.A.	18
TOTAL NUMBER OF GENERA IN B.C.	6
TOTAL NUMBER OF SPECIES IN N.A.	130
TOTAL NUMBER OF SPECIES IN B.C.	14

 

	GENUS ACENTRELLA
TAXONOMIC CHARACTERS	Prothorax with oblique stripes; villopore present; femurs, tibiae, and tarsi edged with a long row of hairs; abdominal segments with paired dorsal spots; gills on all abdominal segments simple; caudal filaments without dark bands every 3rd, 4th, or 5th segment; middle caudal filament less than five segments long; body dorso-ventrally flattened
HABITAT	Among deep riffles and rapids of fast-flowing waters with rocky bottoms
HABIT	Swimming or clinging
FEEDING METHOD	Collecting-gathering
COMMENTS	All species formerly in Pseudocloeon or Baetis
SPECIES RECORDED IN B.C. TO DATE	insignificans, turbida

 

	GENUS BAETIS
TAXONOMIC CHARACTERS	Villopore present; tibiae and tarsi not edged with a long row of hairs, although femurs may have one; gills on all abdominal segments simple; caudal filaments without dark bands every 3rd, 4th, or 5th segment; body cylindrical
HABITAT	Among vegetation or in riffles of shallow, flowing waters; along shorelines of lakes
HABIT	Swimming, climbing, or clinging
FEEDING METHOD	Collecting-gathering or scraping
COMMENTS	Some species an important component of stream drift
SPECIES RECORDED IN B.C. TO DATE	bicaudatus, moffati, parallelus*, persecutus, tricaudatus

*A potentially rare and endangered species, known at present only from the South Okanagan (Scudder 1994).