Photosella charlotteae ( Lowry & Stoddart, 2009 )

Lowry, J. K. & Stoddart, H. E., 2011, The tryphosine genera Photosella gen. nov. and Tryphosella Bonnier, 1893 (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae) in Australian waters 2956, Zootaxa 2956 (1), pp. 1-76 : 6-7

Photosella charlotteae ( Lowry & Stoddart, 2009)

( Fig. 1 )

Tryphosella charlotteae Lowry & Stoddart, 2009: 587 , figs 17, 18.

Type locality. 100 metres north-east of sand spit, One Tree Island , Queensland, Australia, 23°30'S 152°05'E, 1 m depth .

Material examined. Victoria: 1 specimen, MV J3610 , Crib Point, Western Port , 38°21’S 145°14’E, 12 m, coarse sand, Smith-McIntyre grab, 29 September 1964, Marine Studies Group, Fisheries and Wildlife Department, Ministry for Conservation , Victoria, CPBS stn C4; 1 specimen, MV J3614 , Crib Point, Western Port , 38°21.63’S 145°15.08’E, 9 m, sand, Smith-McIntyre grab, 23 February 1965, Marine Studies Group, Fisheries and Wildlife Department, Ministry for Conservation , Victoria, CPBS stn 25S; 1 specimen, MV J3617 , Crib Point, Western Port, 38°21.33’S 145°13.64’E, 15 m, fine sand and mud, Smith-McIntyre grab, 8 April 1965, Marine Studies Group , Fisheries and Wildlife Department , Ministry for Conservation , CPBS stn 31S; 4 specimens, MV J3299 , Port Phillip Bay , 38°00.0'S 144°46.3'E, 11 m, sand, Smith-McIntyre grab, 10 June 1971, stn PPBES 913 ; 1 specimen, MV J3298 , Port Phillip Bay , 38°02.3'S 14444.7'E, 13 m, sand, Smith-McIntyre grab, 10 June 1971, stn PPBES 922 ; 1 male, MV J62293 , 66 km south of Rodondo Island , central Bass Strait , 39°48.6'S 146°18.8'E, 82 m, sand, silt and mud, epibenthic sled, 13 November 1981, R. Wilson, RV Tangaroa , stn BSS-158S . Tasmania: 1 female, 14.5 mm, MV J11262 , 25 km northeast of Deal Island, eastern Bass Strait , 39°14.8'S 147°31.5'E, 57 m, medium sand, Smith-McIntyre grab, 18 November 1981, RV Tangaroa , stn BSS 174G . South Australia: 1 specimen, AM P.69118, 5 km north-west of Port Davis Creek, Port Pirie, Spencer Gulf , 33°16'S 137°51'E, corer, Posidonia sinuosa bed, stn 801-C4/7; 1 female, SAM C 6946, 200 m offshore, north point of Marum Island , Sir Joseph Banks Group , approx. 34º30'S 136º15'E, 6 m, on sponge and under rocky reef, 11 January 1984, W. Zeidler; 1 male, MV J62308 north side of West Island , Encounter Bay , 35°37'S 138°36'E, 4 m, sand patch in Heterozostera meadow, 21 March 1985, G.C.B. Poore & H.M. Lew Ton, stn MV SA-48 .

Diagnostic description. Head lateral cephalic lobe subtriangular, apically rounded; eyes red (fading in alcohol), large, subtriangular with ventral concave lens. Antenna 1 flagellum with strong 2-field callynophore, robust setae absent from proximal articles; calceoli present. Antenna 2 peduncular articles 4 and 5 not enlarged; flagellum short, calceoli absent. Epistome/Upper lip epistome less produced than upper lip, straight. Mandible molar with asymmetrically reduced column, proximally setose, distally triturating. Maxilla 1 outer plate setal-tooth 7, left and right symmetrical, cuspidate along most of straight inner margin; palp distal margin with apical robust setae. Maxilliped outer plate with 2 short apical robust setae.

Gnathopod 1 subchelate; coxa large (length 1.9 x breadth), subrectangular, distally subovate; basis moderately setose along anterior margin; ischium short (length 1.5 x breadth); carpus long (length 2.1 x breadth), subequal in length to propodus, without posterior lobe; propodus margins subparallel, palm moderately acute. Gnathopod 2 propodus palm moderately obtuse. Pereopod 4 coxa with distinct lateral ridge. Pereopod 5 coxa with distinct lateral ridge; basis about as long as broad, with photophore.

Epimeron 3 posterior margin smooth, posteroventral corner broadly rounded. Uropod 3 outer ramus article 2 short, with plumose setae on both rami. Telson deeply cleft, with dorsal robust setae, with 1 or 2 apical robust setae on each lobe.

Male (sexually dimorphic characters). Antennae 1 and 2 calceoli present. Antenna 2 peduncular article 4 slightly enlarged.

Remarks. According to Lowry & Stoddart (2009) P. charlotteae is most similar to P. mucronata ( Pirlot, 1936) . Both species have a well developed photophore on the basis of pereopod 5, but only T. charlotteae has a strong lateral ridge on the pereopod 4 coxa. Lowry & Stoddart (2009) recorded T. charlotteae from the Great Barrier Reef as far south as Moreton Bay. In this paper we extend the range south to Bass Strait.

There is a great deal of variation in the honeycomb appearance of the cuticle in this species. In the material reported by Lowry & Stoddart (2009) there was almost none present; the specimen illustrated in Figure 1 shows a very strong form. We cannot see any pattern to this variation and its loss might be an artefact of preservation.

Distribution. Eastern and southern Australia; 4–15 m and 57–82 m depth.

Figures

FIGURE 1. Photosella charlotteae (Lowry & Stoddart, 2009). Female, 14.5 mm, MV J11262, Bass Strait.