(Figs 7, 8, Pl. 4D)
Type material. Holotype, female, 6.6 mm, AM P71008, Mermaid Cove, Lizard Island, Queensland, Australia (14°38.84’S 145°27.24’E), rubble, bommies and sand patches, 4 m, K. Klebba, L. Hughes & C. Rakocinski, 27 February 2005 (QLD 1709). Paratypes: 1 unsexed, AM P70181, between South and Bird Islands, Lizard Island, Queensland, Australia (14°40'S 145°28'E), rubble with sparse filamentous and abundant encrusting red algae, 8–9 m, B. Kensley, 9 January 1982 (BK 111); 3 unsexed, AM P70182, foot of drop-off, off Coconut Beach, Lizard Island, Queensland, Australia (14°40'S 145°28'E), coarse rubble with Lithothamnion and low algal turf, 17 m, B. Kensley, 19 January 1982 (BK 129); 2 unsexed, AM P70173, reefs at western end of lagoon, Lizard Island, Queensland, Australia (14°40'S 145°28'E), mixed algae, 0–3 m, J.K. Lowry, C. Short, P.C. Terrill, 5 October 1978 (QLD 11); 1 unsexed, AM P70174, off southern Point of Mermaid Cove, Lizard Island, Queensland, Australia (14°39'S 145°27'E), filamentous algae, stone washings and scrapings from crevices, C. Short & P.C. Terrill, 8 October 1978 (QLD 25); 1 unsexed, AM P70175, off North Point, Lizard Island, Queensland, Australia (14°39'S 145°27'E), red algae and coral rubble from subtidal caves, 6.1 m, J.K. Lowry, 14 October 1978 (QLD 49); 7 unsexed, AM P70176 and 1 female, AM P78944, off North Point, Lizard Island, Queensland, Australia (14°40'S 145°28'E), mixed algae, 6.1 m, J.K. Lowry, 14 October 1978 (QLD 50); 1 unsexed, AM P70177, off North Point, Lizard Island, Queensland, Australia (14°40'S 145°28'E), Halimeda, 6.1 m, J.K. Lowry, 14 October 1978 (QLD 52); 1 unsexed, AM P70178, 1.6 km south-west of Eagle Island, near Lizard Island, Queensland, Australia (14°38'S 145°22'E), sediment from coral fans, rubble and dead coral, 7.6 m, 17 October 1978 (QLD 59); 1 unsexed, AM P70179 and 1 ovigerous female, AM P70180, 1.6 km south-west of Eagle Island, near Lizard Island, Queensland, Australia (14°38'S 145°22'E), sponges with some algae and coral rubble, 4 m, J.K. Lowry, 17 October 1978 (QLD 61); 1 unsexed, AM P70183, Clam Gardens, Watsons Bay, Lizard Island, Queensland, Australia (14°39'53"S 145°27'00"E), encrusted calcareous algae on coral, 5.1 m, R. A. Peart, K. Dempsey & M.J. Huggett, 15 November 1999 (QLD 1347); 1 unsexed, AM P70654, Loomis Beach moorings, Lizard Island, Queensland, Australia (14°41'01"S 145°26'52"E), rock at base of mooring on sandy bottom, 3 m, J. Just, 24 February 2005 (QLD 1641); 2 unsexed, AM P70789, Loomis Beach moorings, Lizard Island, Queensland, Australia (14°41'01"S 145°26'52"E), rock at base of mooring on sandy bottom, 3 m, J. Just, 24 February 2005 (QLD 1649); 2 unsexed, AM P778945, Mermaid Cove, Lizard Island, Queensland, Australia (14°38.84’S 145°27.24’E), rubble, bommies and sand patches, 4 m, K. Klebba, L. Hughes & C. Rakocinski, 27 February 2005 (QLD 1709); 1 unsexed, AM P71225 (QLD 1770).
Additional material. 10 unsexed, AM P70277 (EM 1 b); 9 unsexed, AM P70278 (EM 7 b); 30 unsexed, AM P70279 (EM 8.1 a); 16 unsexed, AM P70280 (EM 8.1 c); 3 unsexed, AM P70281 (EM 8.1 d); 1 unsexed, AM P70282 (EM 8.1e); 12 unsexed, AM P70283 (EM 8.1 f); 44 unsexed, AM P70284 (EM 21 i); 2 unsexed, AM P70285 (EM 30 a); 1 ovigerous female and 1 juvenile, AM P70307 (PNG 14); 2 unsexed, AM P30980 (QLD 93); 2 unsexed, P.75696 (QLD 1863); 2 unsexed, AM P75697 (QLD 1920).
Type locality. Mermaid Cove, Lizard Island, Queensland, Australia (14°38'50"S 145°27'14"E), 4 m depth.
Etymology. Named for Jerry Barnard who succeeded Clarence Shoemaker as the amphipod specialist at the National Museum of Natural History, Smithsonian Institution. Amphipods were studied continuously at this institution for 78 years (1914-1992). During this time one of the great world collections of amphipod specimens and literature was amassed and the understanding of amphipod systematics was greatly advanced.
Description. Based on holotype female, 6.6 mm, AM P71008; paratype female, 5.5 mm, AM P78944 and paratype female, AM P70180.
Head and body. Head and body with scattered setae; body without dorsal carina. Head lateral cephalic lobes rounded, with apically rounded margins. Antenna 1 subequal to antenna 2; peduncular article 1 without anterodistal lobe; article 2 long, about 0.5 x article 1; article 3 long, about 0.3 x article 1; accessory flagellum with 4 articles; flagellum without callynophore, robust setae absent from proximal articles, calceoli absent. Antenna 2 less than 40% of body length; peduncle without brush setae; calceoli absent. Mouthparts forming a subquadrate bundle. Epistome/upper lip separate, epistome produced beyond upper lip, concave, not strongly projecting; upper lip produced, rounded apically. Mandible molar a small, smooth flap with finely setose margins; palp attached midway, article 3 without A3–setae. Maxilla 1 outer plate with setal-teeth in 6/5 arrangement; setal-tooth 7, left and right symmetrical, cuspidate medially; setal-teeth B to D short, apically bifurcate; palp distal margin with serrations. Maxilla 2 inner plate about 2 x width of outer plate. Maxilliped inner plates well developed, greater than half the length of outer plate; outer plates without apical robust setae; palp 4–articulate, article 4 well developed.
Pereon. Gnathopod 1 simple; coxa large, about as long as coxa 2, subrectangular with slightly concave anterior margin and broadly rounded anteroventral corner; basis sparsely setose along anterior margin; ischium short; carpus short, subequal in length to propodus, without posterior lobe; propodus longer than broad, margins tapering, with denticulate patch along posterior margin, with 6 robust setae along posterior margin; dactylus inner margin not serrated. Gnathopod 2 chelate; carpus longer than propodus; palm obtuse, concave; dactylus minute. Pereopod 4 coxa with well developed posteroventral lobe. Pereopod 5 coxa equilobate; basis distinctly broader than long. Pereopod 7 basis posterior margin concave.
Pleon. Epimeron 3 posterior margin smooth, posterodistal corner broadly rounded. Urosomite 1 without dorsal depression, dorsally straight. Uropod 1 rami subequal. Uropod 2 rami subequal, inner ramus with strong constriction. Uropod 3 stout; peduncle with dorsolateral flange; rami subequal, without plumose setae; outer ramus 1–articulate. Telson distinctly longer than broad, entire, without dorsal robust setae, with 2 apical slender setae.
Habitat. Living among rubble, sand patches and calcareous algae, 0 to 33 m depth.
Remarks. The only other species in the genus, Shoemakerella cubensis (Stebbing, 1897) and S. lowryi Gable & Lazo-Wasem, 1990, are both known only from the western North Atlantic Ocean. Considering the great distances separating these species from S. barnardi, they are remarkably similar. Lowry & Stoddart (1997) concluded that the only obvious character separating S. cubensis and S. lowryi was the relative length to breadth of pereopod 7 propodus (5.4 times as long as broad in S. cubensis; about 9.5 times in S. lowryi). In S. barnardi the ratio is only about 4.5 times. Shoemakerella barnardi differs from both S. cubensis and S. lowryi in having a distinct concavity on the posterior margin of the basis of pereopod 7.
Shoemakerella barnardi is distinguished from other lysianassid amphipods on the GBR by the scattered setae on the body in combination with the simple first gnathopods.
Distribution. Australia. Queensland: Lizard Island (current study); Heron Island (current study).
Elizabeth and Middleton Reefs (current study). Papua New Guinea. Manunouha Island (current study).