California Department of Fish and Wildlife
Digital Reference Collection of California Benthic Invertebrates

Digital Reference Collection of California Benthic Invertebrates

Family Level | Level 1 Taxonomy | Level 2 Taxonomy

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Orders Habitus Photo
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Distinguishing characteristics


Three "tails" or cerci, with gills on abdomen (either dorsal or lateral, usually plate-like) and one tarsal claw.


Mask-like labium; gills are internalized within the abdomen (Dragonflies) or external on the end of the abdomen (Damselflies).


Two "tails" or cerci; gills (either plumose or finger-like) present on thorax, or on thorax and first few abdominal segments, two tarsal claws.


“Half wings” – first set of wings half membranous and half sclerotized (looks like an “X”); piercing-sucking mouthparts


Well-developed mandibles, four-segmented antennae. Head and abdomen are patterned; the head is also quadrate. Two claws on thoracic legs. Segmented lateral gills on abdomen.


Long antennae, slender legs with single claws. Transparent gills on ventral side of abdominal segments. Mouthparts elongate and unsegmented.


No "tails," just anal prolegs with claws; thorax partially or fully sclerotized, membranous abdomen. May have a "case" built of various materials


Head is distinct with a ring of simple eyes. Thorax and legs are segmented. Prolegs and anal prolegs present on abdominal segments.


No anal prolegs but possibly claws.Bodies of larvae may be completely sclerotized; adults have a hardened first pair of wings ("elytra").


Head may be sclerotized (and visible) or reduced. Legs are not sclerotized. Body fleshy (possibly with clawed prolegs) with various types of breathing structures on the tail end.


Various characteristics, please see non-insects page.