Endevoura inusitata, Lowry, James K. & Hughes, Lauren E., 2015

Lowry, James K. & Hughes, Lauren E., 2015, Endevouridae, a review with description of four new species (Crustacea, Amphipoda, Lysianassoidea), Zootaxa 4018 (1), pp. 1-34 : 3-8

Endevoura inusitata sp. nov.

( Figs 2–6 )

Type material. Holotype female (ovigerous, 4 eggs), 5.5 mm, dissected 5 slides (P 3 in microvial), AM P.69278, North West Shelf, Western Australia, Indian Ocean (19°03'S, 119°02'23"E), 78–80 m, epibenthic sled, 12 December 1982, coll. CSIRO North-West Shelf project, “RV Soela ” (NWS 06.B12.5). Paratype male, 6.0 mm, dissected 5 slides, AM P.69275, North West Shelf, Western Australia, Indian Ocean (19°04'47"S, 118°50'42"E), 81 m, epibenthic sled, 30 October 1983, coll. CSIRO North-West Shelf project, “RV Soela ” (NWS 05.B5.5).

Additional material examined. Western Australia: 1 specimen, AM P.69270, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (1959.0'S, 117°51.4'E to 19°59.4'S, 117°50.4'E), 42 m, epibenthic sled, 18 February 1983, “FRV Soela ” ( CSIRO stn NWS 01-B1-S); 1 male, AM P.69271, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (19°56.9'S, 117°53.5'E to 19°57.3'S, 117°53.2'E), 43– 42 m, epibenthic sled, 18 February 1983, “FRV Soela ” ( CSIRO stn NWS 01-B2-S); 1 specimen, AM P.69272 north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (19°59.3'S, 117°03.6'E to 19°59.6'S, 117°03.0'E), 52 m, epibenthic sled, 22 February 1983, “FRV Soela ” ( CSIRO stn NWS 01- B16-S); 1 male, AM P.69273, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (20°00.3'S, 117°00.4'E to 20°00.5'S, 117°00.0'E), 53 m, epibenthic sled, 22 February 1983, “FRV Soela” ( CSIRO stn NWS 01-B17-S); 1 specimen, AM P.69274, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (20°00.2'S, 117°00.5'E to 20°00.4'S, 116°59.9'E), 52 m, epibenthic sled, 4 September 1983, “FRV Soela” ( CSIRO stn NWS 04-B17-S); 1 specimen, AM P.69276, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (19°04.1'S, 118°47.8'E to 19°04.7'S, 118°47.2'E), 82 m, epibenthic sled, 30 October 1983, “FRV Soela” ( CSIRO stn NWS 05-B6-S); 1 specimen, AM P.69277, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (19°22.0'S, 118°56.0'E to 19°22.1'S, 118°56.4'E), 54 m, epibenthic sled, 8 December 1982, “FRV Soela ” ( CSIRO stn NWS 06-B7-S); 1 female, AM P.69278, north-west of Port Hedland, North West Shelf, Western Australia, eastern Indian Ocean (19°03.0'S 119°02.4'E to 19°03.2'S 119°02.1'E), 80– 78 m, epibenthic sled, 12 December 1982, “FRV Soela ” ( CSIRO stn NWS 06-B12-S); 1 male, NMV J68166 , North West Shelf, between Port Hedland and Dampier, Western Australia (18°41.00'S, 118°39.00'E to 18°41.00'S, 118°39.00'E), 134– 133 m, mud, sand and shell, 4 June 1983, coll. G.C.B. Poore & H.M. Lew Ton, “FRV Soela ” (stn NWA-21); 1 male (66 “E”), 5 mm, dissected 4 slides, NMV J68167 , 35 km north of Cape Wickham, King Island, central Bass Strait (39°13.6'S, 143°55.6'E), 85 m, fine sand, epibenthic sled, 23 November 1981, coll. R. Wilson, RV Tangaroa (stn BSS-205S);

1 male (66 “G”), 3.8 mm, dissected 4 slides, NMV J68168 , 35 km north of Cape Wickham, King Island, central Bass Strait (39°13.6'S, 143°55.6'E), 85 m, fine sand, epibenthic sled, 23 November 1981, coll. R. Wilson, RV Tangaroa (stn BSS-205S); 1 specimen (66 “F”), NMV J68169 , 35 km north of Cape Wickham, King Island, central Bass Strait (39°13.6'S, 143°55.6'E), 85 m, fine sand, epibenthic sled, 23 November 1981, coll. R. Wilson, “RV Tangaroa ” (stn BSS-205S).

Etymology. From the Latin for unusual, extraordinary.

Type locality. North West Shelf, Western Australia, Indian Ocean (19°03'S, 119°02'23"E).

Diagnosis. Head lateral cephalic lobe subacute, ventral margin straight. Maxilla 1 palp article 2 with 8 nodular robust setae and 1 plumose seta. Maxilliped inner plate with 5 nodular robust setae. Gnathopod 1 basis anterior margin smooth, not cuspidate. Coxae 1–3 ventral margin with sparse fine setae. Pereopod 3 carpus posterior margin much shorter than free proximal margin of propodus, posteroproximal margin not produced; propodus length 1.6 × width, anterior margin cuticle with rugose texture, posteroproximal margin produced into a lobe, lobe extending beyond carpus, propodus palm slightly obtuse, convex. Epimeron 3 posteroventral corner subquadrate. Uropod 3 inner ramus shorter than article 1 of outer ramus; outer ramus 2 articulate, article 2 length twice width. Telson slightly longer than broad, length 1.4 × width.

Description of holotype female. Head lateral cephalic lobe subacute, ventral margin straight. Antenna 1 peduncular article 3 visible in medial view; accessory flagellum 4-articulate; primary flagellum 6-articulate. Antenna 2 flagellum 4-articulate. Mandible incisor convex, margin smooth; palp attached proximally, article 2 length 1.3 × article 3. Maxilla 1 inner plate with 2 apical seta; outer plate with 10 setal teeth; palp article 2 with 8 nodular robust setae and 1 slender setae across distal margin and extending down subapical medial margin. Maxilla 2 inner plate subtriangular, smaller than outer plate; outer plate subrectangular. Maxilliped inner plate with 5 nodular robust setae; outer plate with 11 embedded nodular robust setae and 1 slender seta; palp article 4 spatulate. Gills present on pereonites 2–6.

Coxae 1–3 ventral margin with sparse fine setae. Gnathopod 1 simple; basis anterior margin smooth, not cuspidate; carpus length 1.4 × width, 0.8 × propodus length; dactylus posterior margin cuspidate. Gnathopod 2 minutely chelate. Pereopod 3 chelate; merus length 1.1 × width; carpus subquadrate, posterior margin much shorter than free proximal margin of propodus, posteroproximal margin not produced; propodus length 1.6 × width, anterior margin cuticle with rugose texture, posteroproximal margin produced into a lobe, lobe extending beyond carpus, palm slightly obtuse, margin convex. Pereopods 5–6 basis posterior margin expanded; merus posterior margin expanded. Pereopod 7 basis posterior margin excavate distally.

Epimeron 1 posteroventral corner rounded. Epimera 2–3 posteroventral corner subquadrate. Uropod 1 peduncle with 3 lateral and 1 apical robust setae; inner ramus with three lateral robust setae; outer ramus with 1 lateral robust seta. Uropod 2 peduncle with 1 lateral and 2 apical robust setae; inner ramus with lateral 2 robust setae; outer ramus with lateral 1 robust seta. Uropod 3 peduncle without robust setae; inner ramus shorter than article 1 of outer ramus; outer ramus 2 articulate, article 2 length twice width. Telson slightly longer than broad, length 1.4 × width.

Male sexually dimorphic characters. Pereopod 3 not sexually dimorphic propodus similar to female, length 1.6 × width, posterior lobe extending beyond merus, chelation angle 12°; dactylus apically broad.

Remarks. Endevoura species can be separated by the number of robust setae lining the mouthparts of maxilla 1 and the maxilliped. In Endevoura inusitata sp. nov. the maxilla 1 outer plate palp has 8 nodular robust setae while End. mirabilis has 9 and End. prodigium sp. nov. 11 robust setae. The setal counts on the inner and outer plates of the maxillaped are 5 and 11 for End. inusitata , 6 and 8 in End. mirabilis and 7 and 12 for End. prodigium , respectively.

In both End. inusitata and End. mirabilis the basis of the gnathopod 1 anterior margin is smooth while in End. prodigium both sexes have a distinctive serrate margin. On the propodus of pereopod 3 the posterior proximal lobe extends beyond the carpus (and in males further to beyond the merus) in End. inusitata , while the posterior lobe is poorly developed in End. mirabilis and End. prodigium .

Distribution. Indian Ocean: North West Shelf, Australia.

Figures

FIGURE 2. Endevoura inusitata sp. nov., holotype female, 5.5 mm, habitus, AM P. 69278, North West Shelf, Western Australia, Indian Ocean.

FIGURE 3. Endevoura inusitata sp. nov., holotype female, 5.5 mm, AM P. 69278, North West Shelf, Western Australia, Indian Ocean. Scale 0.1 mm.

FIGURE 4. Endevoura inusitata sp. nov., holotype female, 5.5 mm, AM P. 69278, North West Shelf, Western Australia, Indian Ocean. Scale 0.1 mm.

FIGURE 5. Endevoura inusitata sp. nov., holotype female, 5.5 mm, AM P. 69278, North West Shelf, Western Australia, Indian Ocean. Scale 0.1 mm.

FIGURE 6. Endevoura inusitata sp. nov., paratype male, 6.0 mm, AM P. 69275, North West Shelf, Western Australia, Indian Ocean. Scale 0.1 mm.