New Genera of Phreatoicidea (Crustacea: Isopoda) from Western Australia Author Wilson, George D. F. Author Keable, Stephen J. text Records of the Australian Museum 2002 2002-06-01 54 1 41 70 https://journals.australian.museum/wilson-and-keable-2002-rec-aust-mus-541-4170/ journal article 10.3853/j.0067-1975.54.2002.1359 2201-4349 5754788 Peludo paraliotus n.sp. Figs. 8–14 Type material . HOLOTYPE Ƌ, WAM C 25051, bl (body length) 34.1 mm (formalin preserved) . PARATYPES : formalin preserved— WAM C 25052 , Ƌ bl 24.3 mm , ♀ bl 19.3 mm , ♀ bl 16.6 mm ; AM P60532, 11 ƋƋ, 3 ♀♀ , 12 indeterminate specimens; AM P61461 , Ƌ bl 26.1 mm (dissected for SEM ) ; AM P61556 , ♀ bl 19.6 mm (dissected for SEM ) ; AM P61557 , Ƌ bl 28.9 mm (dissected for description and also illustration of pleopods); AM P61558 , ♀ bl 22.3 mm (dissected for description and also illustration of pleopods); ethanol preserved— AM P60533, 26 ƋƋ, 3 ♀♀ , 14 indeterminate specimens—all from type locality, hand and hand sieves, pH 6.57, 11.8°C, G. Wilson, R . Wetzer & S. Keable , 6 September 1999 , WA-597 . Type locality . Stream flowing from swamp at road crossing to le Grand Beach , Cape le Grand National Park , Western Australia , 33°58.75'S 122°07.23'E ( GPS ), under rocks and log, among base of reeds . Other material . WAM C 21976 ( WAM 28–95), Ƌ bl 35.5 mm , Cape le Grand National Park, Western Australia , B. Knott, 20 May 1977 ; series from Cape le Grand National Park, Western Australia , G. Wilson, R . Wetzer & S. Keable, preserved in 95% ethanol— AM P60534, 19 ƋƋ, 3 ♀♀ , 65 indeterminate specimens, freshwater creek flowing into Hellfire Bay, 34°00.18'S 122°09.63'E ( GPS ), reed roots and rocks on edge of gully, sandy substrate (no mud), along steep side of gully 50–75 m from beach, hand sieves, pH 6.7, 17°C, 5 September 1999 , WA-591; AM P60535, 1 Ƌ, 2 ♀♀ , 1 indeterminate specimen, Juncus swamp/peat land behind Hellfire Bay, 33°59.99'S 122°09.72'E ( GPS ), silty wet substrate among roots of Juncus , hand sieves, 5 September 1999 , WA-593; AM P60536, 2 ƋƋ, 3 ♀♀ , 7 indeterminate specimens, perennial Juncus swamp east of Hellfire Bay, 34°00.06'S 122°10.02'E ( GPS ), hand sieves, 6 September 1999 , WA-596. Etymology . The Greek species name paraliotus means “an inhabitant of the seacoast”. Diagnosis . See generic diagnosis. Description based on male . Colouration in life, dark reddish brown, same colour as substrate. In 95% ethanol, dorsal surfaces of head, pereon and pleon grey mottled with pink, lateral surfaces of head, pereon and pleon, and dorsal surface of pleotelson, with dense “fur” of cuticular hairs trapping brown sediment, some pink cuticle exposed on pereopods. When cleaned, lateral surfaces and appendages mostly pink, mottled with grey. Head ( Fig. 8A,C–E ) length shorter than width in dorsal view; width 0.78 pereonite 1 width; lateral profile of dorsal surface smoothly curved; setae absent. Eyes bulging dorsolaterally; maximum diameter 0.24 head depth; dorsal margin convex, ventral margin concave; orientation of longest axis horizontal; ocelli distinguishable as individual units, pigmentation dark. Cervical groove smoothly curved, extending nearly to dorsal margin of head. Mandibular groove present. Mandibular notch present. Clypeal notch present. Pereon ( Fig. 8A ) broad, width exceeding head width; dorsal surface with scattered tubercles and with transverse ridges; setae on dorsal surface absent. Pereonites Figure 8 . Peludo paraliotus n.gen., n.sp. A, holotype Ƌ (WAM C 25051); B, living paratype at type locality (specimen among AM P60532/3); C–E, paratype ♀ (AM P61556); F,G, paratype Ƌ (AM P61461). A, lateral view; B, dorsal view; C–E, head; F, antenna; G, antennula. Scale bar 1 mm. Figure 9 . Peludo paraliotus n.gen., n.sp. A–C,F, paratype Ƌ (AM P61461); D,E,G,H, paratype ♀ (AM P61556). A–H, pleotelson and uropods. Scale bar 1 mm. 2–7 in dorsal view wider than long. Coxal articulation of pereonites 2–4 nearly fused, 5–7 free (although coxa 5 partially fused). Sternal process occurring on sternite 7 (more pronounced in female). Typhlosole absent, gut round in cross section; hindgut caecae absent. Pleonites ( Fig. 9A– C ) in dorsal view 2–4 respective lengths more than half the length of pleonite 5, 1–4 relative lengths unequal, pleonite 4 length greater than pleonites 1–3, 1–4 width 0.78 composite length in dorsal view. Pleotelson ( Figs. 8A , 9 ) lateral length 0.12 body length, 0.66 depth; dorsal length 1.18 width; depth 1.23 pereonite 7 depth. Posterior margin entire, reflexed dorsally, without irregular denticulations; median lobe width 0.5 pleotelson width, produced, greatest length 0.05 pleotelson total length; lateral lobes forming vertical plates, narrower than median lobe, distinct from median lobe, extending beyond median lobe, medial length 0.1 pleotelson total length; median lobe robust sensillate setae absent; lateral lobes robust sensillate setae absent. Dorsal uropodal ridge without setae. Ventral margin anterior to uropods with robust setae, setae denticulate, 7 altogether, posterior seta subequal to anterior adjacent setae. Antennula ( Fig. 8G ) length 0.09 body length, with 12 articles. Tiny aesthetascs on article 7 to terminal article. Terminal article distally oblique, with 2 or more groups of aesthetascs (tiny). Penultimate article length approximately subequal to length of other articles. Distal articles circular. Antenna ( Fig. 8F ) length 0.26 body length. Flagellum length 0.59 total antenna length, with 20 articles. Propodal article 1 absent. Article 5 shorter than article 4, article 6 shorter than articles 4 and 5 combined. Mouthfield ( Fig. 8C,D ) clypeus consisting of broad bar rounded at mandibular fossae, width 0.56 head width. Labrum ventrally semicircular in anterior view, asymmetrical, broadest on right side. Paragnaths ( Fig. 11A ) with distolaterally rounded lobes, having medial and lateral setal rows and thickened medial base covered with cuticular spinules. Mandible ( Fig. 10 ) left spine row with 16 spines (approximately), 6 of which are bifurcate. Right spine row with 14 spines (approximately), 5 of which are bifurcate. Molar process with 1 tooth, complex setulate setae forming posterior row (plumose). Maxillula ( Fig. 11B,C ) medial lobe length 0.85 lateral lobe length; width 0.7 lateral lobe width; with 4 pappose setae; with 2 “accessory” setae, one on distolateral margin and one between central pappose setae, “accessory” setae simple; short weakly setulate seta on distal tip absent. Lateral lobe distal margin with 7 denticulate robust setae, with 6 smooth robust setae; ventral face with 2 plumose setae. Maxilla ( Fig. 11D,E ) medial lobe width 0.78 outer lateral lobe width; proximal portion smoothly continuous with distal portion; proximal and distal setal rows continuous. Outer lateral lobe length subequal to inner lateral lobe, wider than inner lateral lobe. Maxilliped ( Fig. 11F,G ) epipod distal tip pointed. Endite medial margin with 4 coupling hooks on left side, 4 on right side; dorsal ridge with 26 large distally denticulate plumose setae (but only distal setae denticulate). Pereopod I ( Fig. 12A–D ) dactylus length subequal to palm; ventrodistal margin smooth; with 2 distal accessory claws; distal accessory spines absent. Propodus dorsal margin proximal region not protruding. Propodal palm concave, spine-like projections absent; cuticular fringe weakly developed; stout denticulate setae absent; stout robust simple setae conical, 19 altogether; with 20 elongate broad based setae. Merus dorsal margin projection shelf-like and U-shaped (but approaching a spinelike condition), with numerous elongate simple setae. Pereopods II–III ( Fig. 13A ) dactylus without spines on ventral margin; with 1 distal accessory claw. Propodus articular plate present. Basis dorsal ridge in cross section produced and forming distinct plate. Pereopod IV ( Fig. 13B,C ) simple, not prehensile. Dactylus length subequal to propodal palm. Propodus with 12 broad based setae on ventral margin, 1 distinctly larger than others; shorter than dactylar claw. Basis dorsal ridge in cross section angular and produced but not forming distinct plate. Pereopods V– VII ( Fig. 13D ) dactylus with 1 distal accessory claw; spines absent. Propodus articular plate on posterior side of limb present. Basis dorsal ridge distinctly separated from basis shaft, in cross section produced and forming distinct plate. Pereopod VII ischium dorsal ridge forming flange less than shaft width. Penes ( Fig. 13D ) curved posteriorly; length 0.23 body width at pereonite 7, extending past midline and onto pleonite 1; with cuticular hairs on shaft, distally tapering and broadening (broadest medially); distal tip flattened and truncate. Pleopod ( Figs. 9C,F , 12E , 14 ) exopods with lateral proximal lobes on I–V (extending laterally but not extending proximally along protopod on pleopod I), medial proximal lobes on I–V (just extending on to protopod on pleopod I). Endopod I only with setae on margins, setae plumose. Protopods II–V with medial epipods; protopod I lateral epipods linear. Pleopod I exopod broadest proximally, distal margin rounded, dorsal surface lacking setae. Pleopod II endopod appendix masculina shaft proximal half ventral shape in cross section concave, not forming tube; basal musculature pronounced; distal tip broadly rounded; with 51 setae on margin, occurring laterally and medially; length 0.68 pleopod length, distal tip extending near to distal margin of endopod. Uropod ( Fig. 9 ) total length 0.97 pleotelson length. Protopod length 0.53 uropod total length; dorsomedial ridge produced, plate-like, margin smooth; dorsolateral margin setae absent; distoventral margin robust setae absent; ventral ridge without rows of long laterally projecting setae (implicit character state: abundant long “cuticular hairs” present). Figure 10 . Peludo paraliotus n.gen., n.sp. Paratype Ƌ (AM P61461). A,D,G,H, left mandible; B,C,E,F, right mandible. Scale bar 0.5 m. Figure 11 . Peludo paraliotus n.gen., n.sp. Paratype Ƌ (AM P61461). A, paragnaths; B,C, maxillula; D,E, maxilla; F,G, maxilliped. Scale bar 0.5 mm. Figure 12 . Peludo paraliotus n.gen., n.sp. Paratype Ƌ (AM P61461); paratype ♀ (AM P61556). A,B, Ƌ pereopod I; C,D, ♀ pereopod I; E, Ƌ pleopod II appendix masculina. Scale bar 1 mm. Figure 13 . Peludo paraliotus n.gen., n.sp. Paratype Ƌ (AM P61461); paratype ♀ (AM P61556). A, Ƌ pereopod II; B, Ƌ pereopod IV; C, ♀ pereopod IV; D, Ƌ pereopod VII, with penes and articular plate. Scale bar 1 mm. Figure 14 . Peludo paraliotus n.gen., n.sp. A,C,E–G, paratype Ƌ (AM P61557); B,D, paratype ♀ (AM P61558). A,B, pleopod I; C,D, pleopod II; E–G, pleopods III–V. Scale bar 1 mm. Rami distal tips pointed; cross-sectional shape round. Endopod longer than protopod, straight-curving dorsally; dorsal margin robust setae absent. Exopod length 0.87 endopod length; exopod dorsal margin robust setae absent. Sexual dimorphism, female differences from male . Antennula with 11 articles. Antenna length 0.31 body length. Pereopod I dactylus ventrodistal margin with row of thin scalelike spines, along 0.44 total length; propodal palm with 23 elongate broad based setae. Pereopod IV propodus with 9 broad based setae on ventral margin. Uropod total length 1.1 pleotelson length, protopod length 0.55 uropod total length. Remarks . The Hellfire Bay specimens (samples WA591– 593) are not obviously different from those from the type locality. The largest specimens, however, are significantly smaller than those collected near Cape le Grand Beach. Nevertheless, all of our collections of this species from Cape le Grand National Park appear to be conspecific. General distribution and habitat . Cape le Grand National Park, Western Australia ; silty coastal wetlands including Juncus swamps and outflowing streams.