Pacifastacus leniusculus leniusculus ( Dana, 1852 )

Pacifastacus leniusculus leniusculus ( Dana, 1852) View in CoL

( Figs. 1 View Figure 1 , 2 View Figure 2 ; Tab.1)

Description of the syntypes. Eye large (diameter 3.4 mm). Cephalothorax ( Fig.1A View Figure 1 ) subcylindrical, thoracic section dorsoventrally depressed, feebly tuberculated dorsally and dorsolaterally, cephalic section laterally with moderately large tubercles, areola 2.0 times as long as wide, constituting 28.5 % of TCL (38.9 % of POCL). Rostrum ( Fig. 1B, C View Figure 1 ) non-serrate, margins converging from base to base of acumen, broad at base and lacking median carina, with moderately elevated, slightly thickened margins bearing tubercles, weakly converging to base of acumen, with single right (left 1) marginal tubercles; length of acumen greater than width of rostrum at level of marginal spines, margins not constricted at base of acumen, more strongly converging and moderately concave to dorsally directed apex, tip reaching cephalic to distal margin of antennal scale and not reaching distal margin of penultimate podomere of antennular peduncle, acumen comprising 46.8 % of rostrum length, latter comprising 30.5 % of TCL; floor (dorsal surface) of rostrum minutely punctate, suborbital ridge not visible in dorsal aspect, postorbital ridge moderately developed, poorly defined dorsally, with dorsolateral groove, spiniform cephalically and pair of spines at posterior bases.

Carapace as wide as the greatest width of abdomen.

Abdominal pleuron subangular ( Fig. 1D View Figure 1 ) with margins slightly rounded, surface punctate, terga slightly punctate, articular surfaces glabrous. Proximal podomere of uropod ( Fig. 2K View Figure 2 ) with small caudolateral spine on lobe, larger spine on mesial lobe; mesial ramus of uropod with moderate caudolateral spine, and strong median ridge terminating in moderate, submarginal caudomedian spine, lateral ramus of uropod with caudolateral spine; telson with two spines at each caudolateral corner of cephalic section, having transverse suture.

Incisor region of mandible blade-like ( Fig. 2B View Figure 2 ). Antennal scale ( Fig. 2C View Figure 2 ) 2.3 times as long as broad, widest at midlength. Third maxilliped ( Fig. 2D View Figure 2 ) with tip of endopodite extending nearly to distal margin of penultimate podomere of antennal scale peduncle; mesial margin of merus ( Fig. 2E View Figure 2 ) with row of spines, and that of distal end largest; tip of basal podomere of exopodite extending beyond midlength of merus of endopodite, longitudinal ridge of ventrolateral margin of ischium with punctate row, ventrolateral half of ischium punctate, distolateral corner with small tubercle, ventromesial half with long, obscuring bristles on mesial margin, latter with denticles, distomesial corner having large spine.

Epistome ( Fig. 2A View Figure 2 ) with wide, nearly semicircular cephalic lobe, lateral margins of lobe moderately thickened, slightly elevated ventrally, floor (ventral surface) of lobe plane, covered finely punctate, lacking setae; subtruncate lateral corners, lamellae small, punctate; central depression of body broad, fovea weak, lacking spine or ridge posterior to renal papilla; zygoma slightly arched, cephalolateral margins flanked by usual pits.

Total length of cheliped 80.3 % of TCL, mesial margin of palm ( Fig. 1E View Figure 1 ) 0.7 times wider than long, 1.3 times wider than deep, articular ridge strong, dorsal and ventral surfaces punctate, lacking tubercles, distolateral part with weak depression and moderate pits, not costate, articular ridge strong. Fingers of chela not gaping; opposable surface of fixed finger with row of 13 moderate tubercles; lateral surface

A B C

moderate, not having costation and row of tubercles, dorsal surface and ventral surface with tuft of setae originating from pits, lacking longitudinal ridge. Fixed finger dorsolaterally with very weakly costate, dorsal and ventral surfaces with tuft of setae originating from pits, lacking longitudinal ridge, opposable surface with row of 19 conical and equal size tubercles. Dactyl of chelae 1.9 times as long as mesial margin of palm, comprising 56.6 % of total chela length, dorsal surface of dactyl lacking longitudinal ridge, mesial surface with seta originating from pits, ventral surface punctate, lacking ridge; opposable surface with single row of equal size tubercles. Carpus of cheliped 1.3 times as long as wide, 1.1 times length of mesial margin of palm, dorsal surface with long, slightly oblique sulcus, surface lateral and mesial sides along sulcus with pits, mesial surface of carpus with large, strong tubercles, ventral surface with conical distal mounds, distomesial one tipped with spine. Merus of cheliped 2.2 times longer than greatest depth, length 35.1 % of TCL.

Lacking hook on ischia of pereiopods ( Fig. 2F View Figure 2 ). Gonopods (first pleopods) ( Fig. 2G–I View Figure 2 ) of male symmetrical in caudal aspect, well developed, distal portion ( Fig. 2J View Figure 2 ) rolled and contracted to form narrow tube, lacking lobes apically. Length of tubular part 3 times longer than gonopod length; distal portion converging to tip, lacking distal portion corneous.

Deposition and type locality. The syntypic series is comprised of three males: male #1 (USNM 2161), male #2 (USNM 2019) and male #3 (USNM 44408) from Columbia River and Puget Sound, Washington ( Dana, 1852; Hobbs, 1974).