Notorchestia australis ( Fearn-Wannan, 1968 )

Serejo, C. S. & Lowry, J. K., 2008, The Coastal Talitridae (Amphipoda: Talitroidea) of Southern and Western Australia, with Comments on Platorchestia platensis (Krøyer, 1845), Records of the Australian Museum 60 (2), pp. 161-206 : 175-179

Notorchestia australis ( Fearn-Wannan, 1968)

Figs 7–9

Lowry & Stoddart, 2003: 272.

Type material. HOLOTYPE: male, 15 mm, NMV J160 , Hastings , Western Port, Victoria, Australia . PARATYPES: 1 female, 11.5 mm, NMV J161 , same data as holotype .

Material examined. New South Wales: 5 females, AM P 36217, Fisheries Creek,Twofold Bay, on saltmarsh, J. T.van der Velde & S.J. Keable, 19 Sep. 1984; 1 male, AM P 36037, Curalo Lagoon, Twofold Bay, on saltmarsh, S.J. Keable & M.L. Reid, 27 June 1985. Victoria: 1 female, 12 mm, NMV J42333 , Apollo Bay, Victoria, Australia; 5 males and 9 females, AM P68961, Old Port, Port Albert (38°40.03'S 146°40.13'E), narrow beach with a lot of dead Zostera and marsh directly behind, specimens living among Zostera at top of beach and among roots of marsh plants, C. Serejo & J.K. Lowry, 10 Oct. 2003, VIC 125; 1 male and 2 females, AM P68962, among roots of marsh plants under bridge, Painkalac Creek (38°28.01'S 144°5.54'E), C. Serejo & J.K. Lowry, 11 Oct. 2003, VIC 127; 1 female, AM P68963, Peterborough Beach where the river comes into the sea, Peterborough (38°36.6'S 142°52.67'E), freshwater creek with stony bottom, specimens living under stones (freshwater), C. Serejo & J.K. Lowry, 12 Oct. 2003, VIC 133. South Australia: 1 female 11.1 mm, AM P69009 (2 slides, stub J064, SEM micrographs); 1 male, 15.4 mm, AM P69014 (slide), + 236 specimens, AM P68964, beach on west side of breakwater, Port Macdonnell, South Australia (38°3.56'S 140°41.63'E), broad flat beach thickly covered in dead algae and seagrass 3–4 m from water line, C. Serejo & J.K. Lowry, 14 Oct. 2003, SA 137; 2 males, 16.1 mm, AM P69007 (slide, stubs J063, J065–J070), male, 13.3 mm, AM P69008 (left mandible); 15.3 mm (habitus), AM P69006 (stub J083, SEM micrographs) + 116 specimens, AM P68965, beach on west side of breakwater, Port Macdonnell, (38°3.56'S 140°41.63'E), broad flat beach thickly covered in dead algae and seagrass 24 m from water line, C. Serejo & J.K. Lowry, 14 Oct. 2003, SA 138; 1 male and 7 females, AM P68966, Melaluca marsh, Lake Baddy, (37°10.45'S 139°47.41'E), marshland with Juncus and tall marsh grass, C. Serejo & J.K. Lowry, 14 Oct. 2003, SA 141; 1 male, AM P68967, Melaluca marsh beside main fishing port, Robe, (37°9.05'S 139°44.98'E), stones on mud in scraggly Melaluca marsh, C. Serejo & J.K. Lowry, 14 Oct. 2003, SA 143; 60 specimens, AM P68968, Goolwa marsh, Coorong National Park, (35°31.82'S 138°48.51'E), estuarine area with rocks and dry vegetation near water, C. Serejo, J.K. Lowry & J. Bradbury, 15 Oct. 2003, SA 145; 7 males and 3 females, AM P68969, Victor Harbour, Encounter Bay, (35°33.07'S 138°37.44'E), sheltered harbour beach, C. Serejo, J.K. Lowry & J. Bradbury, 15 Oct.2003, SA 146; 84 specimens, AM P68970, beach in Yankalilla Bay, Fleurieu Peninsula (35°28.73'S 138°46.75'E), sandy, rocky beach, C. Serejo, J.K. Lowry & J. Bradbury, 15 Oct. 2003, SA 148; 14 males and 22 females, AM P68971, Lucky Bay, Spencer Gulf, Eyre Peninsula (33°42.48'S 137°2.59'E), broad, flat, sheltered, white sand beach rising in the supra-littoral, C. Serejo & J.K. Lowry, 17 Oct. 2003, SA 151; 4 males and 7 females, AM P68972, small mangrove just north of town, Ceduna, Eyre Peninsula (32°8.87'S 133°40.24'E), small mangrove area with stony substrate, C. Serejo & J.K. Lowry, 19 Oct. 2003, SA 156; 400 specimens, AM P68973, Fowlers Beach, Fowlers Bay, Eyre Peninsula, (31°59.24'S 132°26.26'E), broad beach covered to a depth of at least a meter with dead seaweed, C. Serejo & J.K. Lowry, 19 Oct. 2003, SA 157; 2 males, 1 female, AM P68974, Sleaford Mere, Eyre Peninsula (34°48'S 135°44'E), on stromatolite-like structures on the bottom of salt lake [talitrids living in cracks among calcite structures on the bottom of the lake, so the talitrids were completely submersed in the water—salinity about the same as seawater], B. Timms, 20 Jul 2003, SA 158; 4 males, AM P68975, Sleaford Mere, Eyre Peninsula (34°48'S 135°44'E), on stromatolite-like structures on the bottom of salt lake [talitrids living in cracks among calcite structures on the bottom of the lake, so the talitrids were completely submersed in the water—salinity about the same as seawater], B. Timms, 27 Oct. 2003, SA 159.

Type locality: Hastings , Western Port, Victoria, Australia. On rocky beach found in the damp sand under stones in the inter-tidal zone .

Diagnosis. Mandible left lacinia mobilis 4–5 dentate. Male gnathopod 2, palm smooth, with row of robust setae; dactylus slightly attenuated distally. Coxa 6, posterior lobe posteroventral margins with 1–3 robust setae. Pereopod 7 basis in male tapering distally, lateral sulcus absent, posterodistal corner with 90° angle, lobe absent.

Description

Male, 13.3–16.1 mm. Eye medium, 1⁄5–1/3 head length. Antenna 1 short, rarely longer than peduncular article 4 of antenna 2. Antenna 2 shorter than head and first 3 pereonites; peduncular articles narrow; with sparse, small robust setae. Epistome of upper lip without robust setae. Lower lip, distolateral setal tuft absent. Mandible left lacinia mobilis 4–5 dentate. Maxilliped palp article 2 with mediodistal lobe, article 4 present, reduced.

Gnathopod 1 sexually dimorphic; subchelate; posterior margin of merus, carpus and propodus with rugose lobe; propodus subtriangular; palm transverse; dactylus shorter than palm, simplidactylate. Gnathopod 2 sexually dimorphic; subchelate; palm acute, smooth, with row of robust setae, posterodistal corner with groove; dactylus longer than palm, slightly attenuated distally. Coxae 2–4 as wide as deep. Pereopods 3–7 cuspidactylate; dactylus with row or patch of dorsal short setae. Pereopod 4 subequal or slightly shorter than pereopod 3. Pereopod 4 dactylus thickened and pinched posteriorly, different to pereopod 3 dactylus. Pereopod 5 propodus distinctly longer than carpus. Pereopod 6 not sexually dimorphic; shorter than pereopod 7; coxa posterior lobe anterodistal corner rounded, posteroventral margins with 1–3 marginal setae, posterior margin perpendicular to ventral margin, outer surface with ridge. Pereopod 7 basis sexually dimorphic; basis without lateral sulcus, posterior margin tapering distally, posterodistal corner forming a 90° angle, lobe absent; distal articles slender. Coxal gills simple or slightly lobate. Pereopods 3–5 gills smaller than gills 2 and 6.

Pleopods 1–3 well developed; biramous; inner ramus slightly longer than outer ramus. Pleopod 1 peduncle with 2–3 setae on outer margin and 1 medio-facial seta. Pleopod 2 with 2 setae on outer margin and 4–5 medio-facial setae. Pleopod 3 peduncle outer margin apparently without setae and 8–10 medio-facial setae. Epimera 1–3 posteroventral corner slightly produced into a small subacute spine. Epimeron 3 posterior margin minutely serrate, with setae, ventral margin without setae. Uropod 1, peduncle with 12 robust setae in two rows; distolateral robust seta absent; inner ramus subequal in length to outer ramus; inner ramus with 5 marginal robust setae; outer ramus with 3 marginal robust setae. Uropod 2 peduncle with 7 robust setae in two rows; inner ramus subequal in length to outer ramus; inner ramus with 4 marginal robust setae, 3 on outer margin and 1 on inner margin; outer ramus with 1 marginal robust setae. Uropod 3 peduncle with 3–4 robust setae; ramus subequal in length to peduncle; triangular, narrowing distally; ramus with a sequence of 7–9 marginal slender setae and 5–6 apical setae. Telson longer than broad; incised to half the length; each lobe with 3 lateral robust setae and 1–2 smaller distal robust setae.

Female (sexually dimorphic characters), 15.1 mm. Gnathopod 1 subchelate; posterior margin of carpus and propodus with rugose lobe; propodus subrectangular; dactylus subequal in length to palm. Gnathopod 2 mitten-shaped; basis slightly expanded, about 1.8× longer than wide; carpus well developed, not enclosed by merus and propodus; posterior margin of merus, carpus and propodus with rugose lobe; palm obtuse; dactylus shorter than palm. Pereopod 7 basis not tapering distally, posterodistal corner slightly produced into a small pointed lobe. Uropod 3 ramus with 6 marginal setae.Oostegites longer than wide; setae with simple and multi-furcate tips. Oostegites 2–4 moderately setose (around 24 setae).

mm, H and PL1–3, AM P69007. Scales for H: 1 mm; remainder: 0.5 mm.

Habitat. This species colonized a variety of habitats ranging from the supra-littoral of protected beaches to estuarine areas as salt-marshes.

Remarks. The type material of N. australis ( Fearn-Wannan, 1968) was re-examined and compared carefully with material collected in this study.All the diagnostic characters described in Fearn-Wannan (1968) as well as other characters herein proposed were found in the holotype and the examined material. One exception was the number of teeth on the left lacinia mobilis. The holotype examined has a 5-dentate lacinia although the fifth tooth is very small and the paratypes have a well defined 5-dentate lacinia. On the other hand, all the specimens dissected in the material examined (8) have a 4-dentate left lacinia mobilis. This variation leads to confusion as Bousfield (1982, 1984) used the number of the left lacinia to define genera within the Talitridae . However, variation in the number of teeth on the left lacinia (4 to 5 teeth) of Traskorchestia species was also noted ( Bousfield, 1982). Thus, we decided to maintain this character as an intra-specific variation and consider the ANTS material as N. australis .

Notorchestia australis was commonly found on the South Australia samples occurring in 17 of the 23 stations. It occurs sympatrically with Notorchestia lobata n.sp. in two stations (SA 146 and SA 148).

Distribution. New South Wales: Twofold Bay. Victoria: Old Port, Port Albert; Painkalac Creek; Peterborough Beach (ANTS material). Lake King; Port Philip Bay and Western Port Bay ( Fearn-Wannan, 1968). South Australia: Port Macdonnell; Lake Baddy; Robe; Goolwa marsh, Coorong National Park; Victor Harbour, Encounter Bay; Fleurieu Peninsula;Yankalilla Bay, Eyre Peninsula; Spencer Gulf, Eyre Peninsula; Ceduna, Eyre Peninsula; Fowlers Beach, Fowlers Bay, Eyre Peninsula; Sleaford Mere, Eyre Peninsula.

Figures

Fig. 7. Bellorchestia richardsoni n.sp., holotype male, 20.3 mm, T, EP1–3, AM P60238; paratype male, 22.7 mm, U1–3, AM P69239; paratype female, 21.8 mm, G1–2, AM P69240, Point Ricardo, Victoria. Scales for EP1–3, G1–2: 1 mm; remainder: 0.2 mm.

Fig. 8. Bellorchestia richardsoni n.sp., paratype female, 21.8 mm, O2–5, AM P69240; paratype male, 22.7 mm, PL1–3 and BR2–6, AM P69239. Scales represent 0.5 mm.

Fig. 9. Notorchestia australis (Fearn-Wannan, 1968), male, 15.3 mm, habitus,AM P69006; male, 16.1 mm, other parts,AM P69007, Port Macdonnell, South Australia. Scale for habitus: 1 mm; remainder: 0.1 mm.