provided by Smithsonian Contributions to Zoology
DIAGNOSIS (of female). — Lateral cephalic lobe rounded anteriorly, head with strong anteroventral definition near base of antenna 2, rostrum short, blunt; article 1 of antenna 1 with ventral setae arranged in 2 groups of 2-4 each, article 2 about 1.1 times as long as article 1, apically simple and with 2 sets of ventral spines, flagellum about 1.6 times as long as peduncle; flagellum of antenna 2 about 1.4 times as long as peduncle, multiarticulate; mandibles bearing 2 large spines on right, 3 on left, molar strongly ridged, ragged seta both sides, ordinary long setae both sides; outer lobe of lower lip with 3 long cones, mandibular lobes thick, blunt, straight; palp of maxilla 1 of medium breadth and not reaching apex of outer plate, bearing 4 apical and 1 medial setae, no strong cusps, inner plate thin, naked; inner plate of maxilla 2 much narrower than outer, reaching 80 percent along outer, outer not curved, both appressed, inner with narrow truncate apex and medial setae reaching halfway to base; inner plate of maxilliped long but thin, bearing 4 apical and 2 lateral spines, outer plate of ordinary size, spines bifid or trifid, of medium size, palp slightly exceeding outer plate, dactyl elongate; distal half of coxa 1 significantly narrower than proximal half, part of anterior and all of ventral margins deeply serrate and strongly setose, coxae 2-4 also serrate and setose, coxa 2 rectangular and bearing strong posterior spine, coxa 3 trapezoidal, broad, posteroventrally extended and with strong posterior spine, coxa 4 broad, softly rounded posteroventrally, coxae 5-6 weakly spinose ventrally; gnathopods stout, gnathopod 1 with article 6 about 0.85 times as long as article 5, in gnathopod 2 about 0.90 times, palm slightly oblique, extremely finely serrate; dactyls short, medial oblique setal row of hand with 6 plumose spines, anterofacial setae on gnathopod 1 in rows of 8 and 1, dactyls smooth proximal to main inner tooth; pereopods stout, spines stout but sharp, ratio of articles 4-7 on pereopods 1-2 about 26:15:26:13, outer distal spinule of dactyl attached unusually proximally; article 2 of pereopod 3 slightly stout, posteroventral lobe poorly developed, article 2 of pereopod 4 ovatopyriform, posteroventral lobe obsolete, posterior margin sparsely spinose, article 2 of pereopod 5 quadrate but with posteroventral bevel, no posteroventral lobe but posterior and posteroventral margins spinose, ratio of articles 4-7 about 25:25:18:11; pleonal epimera 1-2 with lateral ridge and weak posteroventral tooth, epimeron 3 with small posteroventral tooth, posterior margins of epimera minutely ragged, epimeron 1 with about 8 short ventral setae, epimeron 2 with 1 ventral seta, epimeron 3 with about 6 ventral spinules in tandem; pleonite 1 dorsally smooth, pleonites 2-3 with small sharp dorsal tooth and side tooth, dorsal tooth on 3 placed anteriad, pleonite 4 with large erect sharp dorsal tooth, large lateral tooth and lateral spine; pleonites 5-6 (fused) with 2 dorsolateral spines on each side; dorsal margin of peduncle on uropod 1 evenly spinose; inner ramus of uropod 3 with plumose setae besides spines; telson flat, apices of lobes narrow, each bearing deep notch armed with small spines, each medial projection weakly bifid, lateral margins of lobes each with 4 small-to-medium spines; cuticle of dorsal parts of posterior body segments covered with numerous minute villi or papillae.
MALE (based on 3.8 mm, JLB Australia 4). — Male characters not fully developed, teeth of pleonite 2 poorly developed, dorsal tooth of pleonite 4 projecting completely erect; apex of each telsonic lobe truncate, quadratiform; following characters like female: maxillipeds, plates and palp of maxillae, cones of lower lip, mandibles, epimera, pereopods, coxae.
JUVENILES (smallest, 1.5 mm, based on JLB Australia 4 (1), 5 (3). — Lateral ridges on pleonite 3 weak, middle tooth obsolete, teeth absent on pleonite 2 but distinct on pleonite 4; other juveniles developing middle tooth on pleonite 2 with lateral teeth added in larger juveniles (or those better developed morphologically); size and morphological development not necessarily congruent.
HOLOTYPE. — WAM, female, 5.3 mm.
TYPE-LOCALITY. — JLB Australia 4, Sugarloaf Rock, Cape Naturaliste, Western Australia, intertidal, wash of algae, mainly green Caulerpa species, 1 September 1968.
RELATIONSHIP. — This species is close to P. narluke (q.v., for a discussion of relationships).
A few distinctions of similar species are mentioned in the following statements: Paradexamine windarra has a well-developed lobe on article 2 of pereopod 5, a small inner plate on the maxilliped, and a less bizarre coxae 1-4 than does P. goomai. Paradexamine otichi has coxae similar to those of P. goomai but has a poorly developed flagellum on antenna 2, a sublobate article 2 of pereopod 5, a spination gap on the peduncle of uropod 1, transverse palms of the gnathopods, smooth mandibular molars, and no cones on the lower lip. Paradexamine quarallia has characteristically blunt dorsal teeth, a normally expanded coxa 1, a lobe on article 2 of pereopod 5, and a small inner plate on the maxilliped. Paradexamine frinsdorfi has a poorly developed flagellum on antenna 2, a protrusion anteriorly on coxa 1, an enlarged inner plate on maxilla 1, and a quadropyriform article 2 on pereopod 5. Paradexamine ronggi also has a short flagellum on antenna 2 and characteristically mitten-shaped hands on the gnathopods.
Paradexamine goomai resembles P. muriwai J. L. Barnard (in press) from New Zealand but differs from it in the less strongly defined anteroventral cephalic corner, the short palp of maxilla 1, the long inner plate of the maxilliped (in the female), the different pattern of medioanterior setae on the hand of gnathopod 1 (compare Figures 47–49 and J. L. Barnard, in press), the serrate coxae, the posteroventrally extended coxa 3, the sharpness of spines on all pereopods, the narrower article 2 and shorter article 5 of pereopod 5, and the narrower apices of the telson, bearing only 1 (not 2) apical spine.
MATERIAL. — JLB Australia 4 (2), 5 (4), 6 (1).
DISTRIBUTION. — Southwestern Australia, intertidal.
- bibliographic citation
- Barnard, J. L. and Drummond, M. M. 1978. "Gammaridean Amphipoda of Australia, Part III. The Phoxocephalidae." Smithsonian Contributions to Zoology. 1-551. https://doi.org/10.5479/si.00810282.103