Cancridae, Latreille, 1802

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 227-228

Key to species of family Cancridae

1. Front markedly projecting beyond outer orbital angles, with 5 subequal teeth. Carapace with 5 broad anterolateral teeth............................................................................................ Cancer productus

– Front not markedly projecting beyond outer orbital angles, with 5 or more unequal teeth. Carapace with 5 or more curved, acute or widely separated anterolateral teeth................................................................ 2

2. Adults small, carapace length not more than 40 mm. Carapace with sharply elevated regions bearing coarse, rounded granules. Chelipeds with granulated tubercles or spines on upper part of manus, carpus...................................... 3

– Adults large, carapace length more than 40 mm. Carapace smooth or with small granules concentrated on moderately raised areas. Chelipeds smooth or with sharp spines or granules...................................................... 4

3. Carapace widest at seventh or eighth tooth, with conspicuous raised, granulate areas, 12 or 13 anterolateral teeth, anterolateral margin not meeting posterolateral margin at distinct angle. Small, rarely south of Point Arena , California ............................................................................................... Glebocarcinus oregonensis

– Carapace widest at ninth anterolateral tooth, with raised, granulate areas but not as prominent as in preceding species, 9 or 10 anterolateral teeth, anterolateral margin meeting posterolateral margin at distinct angle. Larger, generally found south of Point Conception..................................................................... Glebocarcinus amphioetus

4. Carapace with anterolateral teeth not strongly produced or forward curving, front slightly produced (if at all), with triangular medial tooth, chelipeds smooth to spiny.................................................................... 5

– Carapace with anterolateral teeth strongly produced, curving forward, front moderately produced, with acute medial tooth; chelipeds with sharp spines or granules along carinae of outer, upper surfaces of manus, carpus (may be blunt in very old animals)............................................................................................... 7

5. Carapace widest at tenth anterolateral tooth; no eleventh tooth. Usually found north of Point Conception on sand, carapace width to 230 mm .................................................................... Metacarcinus magister

– Carapace widest at ninth anterolateral tooth; with tenth, sometimes eleventh tooth. Found north or south of Point Conception on sand or among rocks, carapace width to 91 mm ........................................................... 6

6. Pereopods 2–5 flattened. Fingers of chelipeds without dark color, chela without orange blotch on inner surface of palm. Merus of third maxilliped rounded anteriorly.................................................... Metacarcinus gracilis

– Pereopods 2–5 rounded in cross section. Fingers of chelipeds ending in dark color, chela with orange blotch on inner surface of palm. Merus of third maxilliped not rounded anteriorly..................................... Metacarcinus anthonyi

7. Carpus of cheliped with single spine at distal end, hand smooth or granulated. Inner surface of cheliped with red spots........................................................................................ Romaleon antennarius

– Carpus of cheliped with two spines at distal end, hand roughened, armed with two spines (may be inconspicuous). Inner surface of cheliped without red spots........................................................................ 8

8. Tenth anterolateral tooth conspicuous, eleventh present; dactyl of cheliped spiny. Carapace with prominently raised areas......................................................................................... Romaleon branneri

– Tenth anterolateral tooth inconspicuous, eleventh not present; dactyl of cheliped not spiny. Carapace with slightly raised areas...................................................................................... Romaleon jordani