Glandulotiron septimus, Just, 2022

Just, Jean, 2022, Tirons of the world: a review of ‘ tironid’ amphipods, description of new genera and species, and establishment of a new subfamily Tironinae Stebbing, 1906 stat. nov. (Crustacea, Synopiidae), Zootaxa 5139 (1), pp. 1-89 : 45-48

Glandulotiron septimus sp. nov.

( Figs 25–26 )

Type fixation. Holotype, ♀. — Here designated.

Etymology. This species was the seventh of the new species in the genus to be recognised, hence the Latin septimus .

Material examined. Holotype, ♀, 6.2 mm. Australia, Bass Strait , 94 km N of North Point, Flinders Island, 38˚53.42’S, 147˚55.06’E, 71 m, medium sand, R. Wilson, 17 November 1981, RV Tangaroa , stn BSS171 , NMV J73766 .

Paratypes. Same data as holotype, NMV J75155 (♂) . Same data as holotype, NMV J75156 (13 specimens) . Same date as holotype, NMV J73772 (5 small specimens) . Same data as holotype, NHMD 916114 (5 specimens) . Australia, Victoria, Western Bass Strait , 30 km SSW of Warrnambool, 38˚38’12’’S, 142˚35’00’’E, 59 m, R. Wilson, 20 November 1981, stn BSS188 , NMV J73751 , (2 specimens) . Australia, Tasmania, Eastern Bass Strait, 79 km N of North Point, Flinders Island , 39˚05.12’S, 147˚56.36’E, 62 m, shelly sand, R. Wilson, 17 November 1981, RV Tangaroa , stn BSS172 , NMV J73757 (1 ♂) . Australia, Central Bass Strait , 65 km S of Cape Schanck, 39˚08.3’S, 144˚43.9’E, 66 m, coarse sand, R. Wilson, 23 November 1981, RV Tangaroa , stn BSS201 , NMV J73758 , (1 ♀) . Australia, Tasmania, Central Bass Strait, 35 km N of Cape Wickham, King Island , 39˚134’36’’S, 143˚55’36’’E, 85 m, fine sandy shell, epibenthic sled, R. Wilson, 23 November 1981, RV Tangaroa , stn BSS 205 , NMV J73763 (1 ♂) . Australia, Tasmania, Eastern Bass Strait, 79 km N of North Point, Flinders Island , 39˚05.12’S, 147˚56.36’E, 62 m, shelly sand, R. Wilson, 17 November 1981, RV Tangaroa , stn BSS172 , NMV J73767 (8, ♀♀ and small) . Australia, Tasmania, Eastern Bass Strait, 79 km N of North Point, Flinders Island , 39˚05.12’S, 147˚56.36’E, 62 m, shelly sand, R. Wilson, 17 November 1981, RV Tangaroa , stn BSS172 , NMV J73768 (2 ♀) . Australia, Western Bass Strait , 51km SSW of Cape Otway, 39˚16’S, 143˚17’E, 90 m, medium sand, G.C.B. Poore, 10 October 1980, HMAS Kimbla , stn BSS72 , NMV J73770 (1 ♀) . Australia, Central Bass Strait , 65 km S of Cape Schanck, 39˚08.3’S, 144˚43.9’E, 66 m, coarse sand, R. Wilson, 23 November 1981, RV Tangaroa , stn BSS201 , NMV J73771 (1 juvenile) .

Description (female). Head dorsal surface smooth. Rostrum bluntly rounded. Interantennal lobes broad, elongate truncate with rounded corners, lower corner more angular than upper corner. Accessory eyes composed of 5 ommatidia, appressed in crescent.

Mouthparts. Maxilla 1 palp apex with 5 short up to 5-dentate setal spines and 1 pointed lateral seta. Mouthparts otherwise normal.

Antenna 1 as long as pereonite 1–5 combined along dorsum, peduncle article 2 about 3/4 length of 1, article 3 about half as long as article 2, article 1 with single penicillate seta ventrally in posterior half and two middorsally; flagellum as long as peduncle, of 7 articles, accessory flagellum of 4 articles. Antenna 2 as long as pereonites 1–6 combined along dorsum, peduncular article 4 the longest, flagellum of 5+ articles, several articles with single slender robust seta dorsodistally, antenna otherwise sparsely setose.

Coxal plates 1–3 distally fringed with setae of varying length, without brim of fine setules; plate3 distally obliquely truncate with a few marginal setae. Coxal plate 4 essentially naked.

Gnathopods 1 and 2 basis with a few long and short anterior setae, and longer setae along posterior margin; carpus on both with a few long setae on anterior margin, 6–8 ‘groups’ of unequally long setae along posterior margin, more dense on gnathopod 1; propodus slightly less than half as long as carpus; dactylus with unguis half as long as propodus, nearly straight. Gnathopod 1 propodus with row of 5 short, pectinate setae on posterior margin. Gnathopod 2 propodus posterior margin with scattered slender setae.

Pereopods 3–4 basis nearly naked, with a few setae in posterodistal corner.

Pereopods 5-7 basis broadly rounded distally. Pereopod 5 basis broadest in distal half, with short posteroproximal lobe. Pereopod 6 basis ovoid. Pereopod 7 basis broadest proximally with broad posteroproximal lobe, with a few long setae on medial surface, posterior margin crenulate with tiny setae in indentations, propodus about half as long as carpus.

Uropod 1 peduncle reaching about 2/3 along peduncle of uropod 2 peduncle, rami of equal length, about 3/4 length of peduncle, reaching to end of rami of uropod 2. Uropod 2 rami of subequal length. Both uropod 1 and 2 reaching about 1/3 along outer ramus of uropod 3. Uropod 3 peduncle about 3/4 length of outer ramus, rami elongate oval, reaching beyond apex of telson, outer ramus basal article with row of 5 robust setae dorsally, and 4 tiny robust setae ventrally, small second article with 3 dorsal robust setae; inner ramus reaching to 9/10 of basal article of outer ramus, dorsal margin with row of long setae and 2 robust setae, apex with 3 robust setae.

Telson. Length about 2.5 times greatest depth in lateral view, reaching 2/3 along outer ramus of uropod 3, length/dorsal width 2.3, with row of 4 robust setae, simple setae and one plumose seta dorsally on each lobe, apices with 1 long and 1 short robust seta.

Size. Largest ♀, 6.2 mm. Largest ♂ 6.3 mm.

Distribution. Australia, Bass Strait, 62– 90 m.

Figures

FIGURE 25. Glandulotiron septimus gen. et sp. nov. Holotype, ♀, except F, ♀ paratype. clv, head lateral view; gp1–gp2, gnathopods 1 and 2; mx1, maxilla 1; us, urosome.

FIGURE 26. Glandulotiron septimus gen. et sp. nov. Holotype, ♀, except F, ♀, paratype. cx3, coxal plate 3; p4–p7, pereopods 4 to 7; tel, telson.