Fortuynia inhambanensis, Marshall & Pugh, 2002

Marshall, David J. & Pugh, Philip J. A., 2002, Fortuynia (Acari: Oribatida: Ameronothroidea) from the marine littoral of southern Africa, Journal of Natural History 36 (2), pp. 173-183 : 174-176

Fortuynia inhambanensis sp. nov.

(®gures 1, 2)

Material. More than 60 individuals were collected from ®nely branched, upper littoral rocky shore seaweeds at Tofo, near Inhambane, Mozambique (23ss47¾ S, 35ss22¾ E) (D. J. Marshall, December 1997) . Specimens were preserved in 70% ethanol, cleared in lactic acid and slide mounted in glycerine or Hoyer’s medium. Seven females were examined. Illustrations were based on temporary cavity-mounte d specimens. All measurements are given in micrometres (Mm). The notogastral setal notation follows the unide®cience nomenclature. The holotype and two paratypes will be deposited in the Natural History Museum , London, UK , and four paratypes in the National Museum , Bloemfontein, South Africa .

Etymology. Speci®c name refers to the collection locality.

Idiosoma. Female, 372±390 Mm long, 210±217 Mm wide. Brown to dark brown. Oval.

Prodorsum. Surface ®nely punctate. Lamellar ridge development variable. Rostral setae smooth (30±38 Mm), lamellar setae smooth (25±35 Mm), interlamellar and exobothridial setae vestigial. Bothridium rounded and partially shielded in dorsal view by notogastral margin. Sensillus typically smooth and hyaline, sharply incurving, clavate and relatively large with a very short stalk. Van der Hammen’s organ comprises dorsosejugal, notogastral and lateral channels, but prodorsal channels (ce and ci) absent.

Notogaster. Surface smooth and punctate. Brown with lighter areas anteriorly (a probable lenticulus). Dorsosejugal suture complete and medially straight (transverse). Notogastra l setae number 14 pairs, are long, thick, ®nely pointed and smooth. Separation of setae c1 greater than distance c1±c2. c3 seta absent with no apparent vestige. da anterior to or level with la, and dp half as long as other dorsal setae. Setae h2 longer than h3. Setal lengths (range for ®ve individuals) as follows: c1 35±40, c2 20±27, da 40±45, dm 30±34, dp 17±24, la 30±38, lm 28±31, lp 25±32, h3 18± 24, h2 43± 48, h1 20±29, ps3 20±23, ps2 29±33, ps1 37±45. Lyri®ssures ia anterior to c2, im between setae lm and lp. Lyri®ssures ih, ip and ips could not be seen. Glandular openings (gla) posterio-lateral to im.

Venter. Surface lightly punctate. Foveate plastron extends along the outer margin of coxisternum, from acetabulum I to IV, medially along epimeral border III, and posteriorly on ventral plate below notogaster. Epimeral setation typically 3-1-3-2. Epimeral setae short (10±17 Mm) except 1b (27±35 Mm). Genital and anal plates the same colour as the ventral surface and epimeral plates. Genital plates 14

at of by markedly rectangular and large (81±88 Mm long and 40±45 Mm wide), each typically bearing ®ve setae (10±16 Mm). Anal plates large (79±88 Mm long and 32±36 Mm wide), each typically bearing two setae (18±25 Mm). Anal plate interlocking piece (preanal organ) large and dark. Aggenital setae absent. Adanal setae ad2 and ad3 anterior of lyri®ssure iad. Setae ad2 and ad3 of similar length (18±25 Mm), but ad1 notably longer (26±34 Mm). Subcapitular seta h, long.

14

at of by

Legs. Femora and genua of all legs dark brown and ®nely pitted. Slight darkening of proximal and distal ends of tarsus and tibia, respectively. Lengths of femur, tibia, tarsus and claw (rounded mean in Mm; n 54): leg I 94, 47, 40, 30; leg II 84, 40, 33, 30; leg III 60, 44, 36, 30; leg IV 67, 55, 40, 30. Setation of genua diagnostic: genu I: seta d long and smooth, abaxial lateral setae l ², long and barbed, adaxial l ¾, a very short, blunt spine; genu II: setae l ¾ and l ² both barbed and approximately half as long as the smooth dorsal seta (®gure 2 B). Tarsi each with a single relatively thick and hooked claw, shorter than the tarsus.