Alismobates pseudoreticulatus, Pfingstl, Tobias, 2015

Pfingstl, Tobias, 2015, The intertidal Fortuyniidae (Acari: Oribatida): new species, morphological diversity, ecology and biogeography, Zootaxa 3957 (4), pp. 351-382 : 366-373

Alismobates pseudoreticulatus sp. nov.

Type material — Holotype: male, Singapore, Pulau Ubin; 28 Oct. 2012; algae growing on rocks; leg. I. Bartsch. Deposition of holotype: Naturhistorisches Museum Wien/NHM Vienna, Austria; collection Nr. NHMW 27.594.

Etymology. This species is very similar to Alismobates reticulatus Luxton, 1992 , but shows only a rudimentary reticulate pattern on the notogaster, therefore the specific name refers to the similarity to this species.

Diagnosis. Average length 293 µm, mean width 211 µm. Notogaster rounded, nearly circular in shape. Obvious prodorsal lamellar ridges. Sensilla long, clavate, distally spinose. Lenticulus pear-shaped. Conspicuously granular longitudinal bands on each lateral side of notogaster. Two longitudinal bands showing faint and incomplete reticulate pattern framing centrodorsal notogastral setae. Notogastral setae 14 pairs, c3 absent. Epimeral setation 3-1-2-1. Aggenital setae 1 pair.

Description of adult. Females (N=2), length: 292–308 µm (mean 300 µm), width: 215 µm (mean 215 µm); males (N=1), length: 280 µm, width: 203 µm.

Integument. Colour dark brown.

Prodorsum. Cerotegument granular, larger granules in median area between bothridia. Cuticle brown laterally, median interlamellar area lighter coloured. Rostrum triangular in dorsal view, slightly projecting anteroventrally in lateral view. Rostrum demarcated from remainder of prodorsum by transverse ridge. Rostral setae (ro) simple (approx. 30 µm), lamellar setae (le) thin, shorter (approx. 10 µm). Strongly sclerotized broad lamellar ridges bearing lamellar setae. Interlamellar setae (in) thin, short, exobothridial setae (ex) fine, very short. Bothridia small cups with very narrow orifice and lateral incision. Sensilla long, clavate, distally spinose.

Gnathosoma. Pedipalps pentamerous 0-2-1-3-9 (including solenidion). Solenidion ω on tarsus erect, not associated with eupathidium acm. Large porose area on paraxial ventral side of femur. Chelicerae chelate, movable digit slightly darker sclerotized, with 3 small, blunt but distinct teeth, fixed digit with 2 teeth, all teeth interlocking. Large lateral porose area from middle of chelicerae to joint of digits. Setae cha and chb of approximately same length, both dorsally slightly pectinate. Genae well sclerotized, finely granular. Distal part of rutellum developed as thin triangular slightly curved inward membrane with longitudinal incision. Setae a and m long, smooth. Mentum regular, finely granular, setae h simple, long.

Gastronotic region ( Fig. 11 A). Notogaster nearly circular in dorsal view. Cerotegument finely granular. Broad longitudinal band on each lateral side showing larger and distinct granulation. Two longitudinal bands showing faint and incomplete reticulate pattern framing centrodorsal notogastral setae. Lenticulus more or less pear-shaped with irregular borders. Notogastral setae (length 10–30 µm) thin, simple, 14 pairs: c1-2, da, dm, dp, la, lm, lp, h1-3, p1- 3; c3 absent. Notogastral lyrifissures 5 pairs: ia next to seta c2, im posterior and laterad of seta lm, ih laterally, ip laterad and anterior of seta p3, ips next to p2. Orifice of opisthonotal gland gla laterally, between levels of setae lm and lp.

and their Solenidia - - 2 2 1 2 2 1 - - 1 1 - - 1 1 - 1 - 1 - - 1 0 1 - - 1 0 1 1 - 0 0 - 0 - 0 - 1 setae of Chaetome 2 18 - - 4 - - 0 3 - 4 - - - 18 2 0 3 2 - 2 4 - - 15 0 - 15 2 0 - 3 4 - - - - 1 2 - 15 1 - 1 - - - - 1 3 - 15 1 3 - 2 2 12 - 2 - 1 - 1 - 2 - - - 2 2 12 development (it) ω) it First ω ε (ω, ()) it ´´ ft ..,), ft, adult stage ft,)) (ft) (, tc ((,) tc),) (to tritonymph preceding Tarsus u (,,) (( p tc) - (, tc (u (p),) -) u ,, p (,)) (- p ,, a)) s ((, - to a) (,, (a,) s (a, u,) (from regard,) pv, s), pv s) pv, (pv (solenidia with change pl (), ((

and no φ = φ φ

Chaetome of -, setae Tibia l (),, φ ´v -´l ,,´v ´´ l,´φ v l) (´l v ´´ ,, - nov. pairs Genu l,) (σ - l), (σ - l´, σ -´l d, -. = sp))) l l ( pseudoreticulatus by letters. indicated Femur Trochanter bv, ´´ d, - (- -,, ´´ bv d - (- - d ev v´´, l´- ev´´v d, - - Alismobates 3. homologies Instars tritonymph adult tritonymph adult tritonymph adult tritonymph adult TABLE I Leg II Leg III Leg Leg IV TABLE 4. F. smiti . Leg setation from larva to adult. First development of setae and their homologies indicated by letters. () = pairs of setae, - = no change with regard to preceding stage.

Instars Trochanter Femur Genu Tibia Tarsus Chaetome Solenidia

I larva - d, bv´´(l), σ (l), v´, φ (pl), (pv), s, (a), (u), (p), (tc), (ft), ε ω 0-2-2-3- 16 1-1- 1 adult v´ - - l´´- 1-4-2-3- 15 1-1-1

III larva - d, ev´l´, σ v´, φ (pv), s, (a), (u), (p), (tc), (ft) 0-2-1- 1-13 1-1 -0 protonymph - - - - - 0-2-1- 1-13 1-1 -0 deutonymph v´ - - - - 1-2-1- 1-13 1-1 -0 tritonymph - l´ - - (it) 1-3-1-2-15 1-1-0 adult - - - l´´- 1-3-1-3-15 1-1-0

IV protonymph - - - - (pv), (u), (p), ft´´0-0-0-0-7 0-0-0 deutonymph - d, ev´d v´, φ s, (a), (tc) 0- 2 -1-1-12 0-1-0 tritonymph v´- l´l´ - 1-2-2-2-12 0-1-0 adult - - l´´- 1-2-2-3-12 0-1-0 Lateral aspect ( Fig. 11 C). Cerotegument finely granular, larger granules on pedotectum I and in acetabular regions. Pedotectum I present, round, small. Cuticular canals of van der Hammen’s organ typical for the genus Alismobates .

Ventral region of idiosoma ( Fig. 11 B). Cerotegument finely granular in sternal region, larger granules laterally next to acetabula. Irregular cuticular ridges on posterior border of epimeron III and IV. Epimeral setation 3-1-2-1, all setae thin, smooth. Genital setae 5 pairs, short, fine; aggenital setae short, 1 pair. Anal valves triangular, 2 pairs of anal setae an1-2. Preanal organ triangular. Adanal setae (an1-3) 3 pairs, short, simple. Setae ad3 on level with anterior border of anal opening, ad2 laterad, ad1 posterior of anal valves. Lyrifissure iad orientated longitudinally, flanking posterior third of anal orifice.

Legs ( Fig. 12 ). Monodactylous. Long hook-like claws. Cerotegument finely granular. Cuticle heterogeneous, trochanters dark, proximal third of femur I and II light remainder dark, femora III and IV dark, all genua dark, all tibiae light and proximal part of all tarsi slightly darker than distal part. Femora without ventral carinae. Large porose areas on paraxial side of femora I and II, paraxial porose areas dorsally on femora III and IV. Kidney-shaped porose areas on dorsal paraxial aspect of trochanter III and IV. All tarsi with proximal lyrifissure. Antiaxial lateral seta l on all genua obviously thickened and blunt. Chaetome and solenidia see table 3.

Description of tritonymph. (N=2): length 262–292 µm (mean 277 µm).

Integument. Colour brown. Plicate and soft except for large centrodorsal plate.

Prodorsum. Cerotegument finely granular. Rostral setae (ro) robust, lamellar setae (le) also robust, inserting on slender lamellar ridges. Interlamellar (in) and exobothridial setae (ex) minute. Bothridia small cups, laterally opened. Sensilla long, clavate, distally spinose. Paired porose area on median posterior region of prodorsum.

Gnathosoma. No difference from adult stage.

Gastronotic region ( Fig. 13A ). Large centrodorsal plate showing reticulate surface pattern. On posterior third of gastronotic region inverted Y-shaped area with granular surface. Circular porose areas associated with bases of setae located on centrodorsal plate. Large folds framing centrodorsal plate. Notogastral setae simple, short, 15 pairs: c1-3, da, dm, dp, la, lm, lp, h1-3, p1-3. Orifice of opisthonotal gland gla located in ventrolateral folds.

TABLE 5. Habitats of the fortuyniid genera Fortuynia , Alismobates and Circellobates inferred from information on sampling localities

given in literature.

species description of sampling locality classification of habitat authors

. arabica intertidal algae littoral rocky shore Bayartogtokh et al. 2009

. atlantica algae and empty barnacles littoral rocky shore Krisper & Schuster 2008

. elamellata rock crevices littoral rocky shore Luxton 1967

. e. micromorpha barnacles, oyster shells and shale deposits littoral rocky shore Marshall & Pugh 2002

. e. shibai rock covered with sea algae and empty shells of oysters littoral rocky shore Aoki 1974

. inhambanensis seaweeds on rocky shore littoral rocky shore Marshall & Pugh 2002

. longiseta n.sp. algae on intertidal rocks littoral rocky shore -

. maculata red and green algae on coral cliffs littoral rocky shore Luxton 1986

. maledivensis n.sp. algae on intertidal rocks littoral rocky shore -

. marina red algae on intertidal stones littoral rocky shore Hammen 1960

. rotunda roots of mangroves mangroves Marshall & Pugh 2002 bark from mangrove tree, algae on floor of mangrove forest mangroves Karasawa & Aoki 2005

. sinensis barnacles and red algae on rocky shore littoral rocky shore Luxton 1992

. smiti water sample from a river freshwater stream Ermilov et al. 2013

algae on intertidal rocks littoral rocky shore -

. taiwanica intertidal algae littoral rocky shore Bayartogtokh et al. 2009

. yunkeri empty barnacle shells on rock littoral rocky shore Hammen 1963

. inexpectatus algae on rocks and mangrove roots littoral rocky shore / mangroves Pfingstl 2013

. pseudoreticulatus n.sp. algae on intertidal rocks littoral rocky shore -

. reticulatus red and green algae at high water mark littoral rocky shore Luxton 1992

bark from mangrove tree, algae on floor of mangrove forest mangroves Karasawa & Aoki 2005

. rotundus green algae in mangrove mangroves Luxton 1992

. venustus sediment upper littoral, barnacles and oyster littoral sandy shore Luxton 1992 Ventral region of idiosoma ( Fig. 13 B). Specific pattern of furrows and folds typical for juveniles of this genus. Series of pores leading into tracheal tubes arranged along ventrosejugal furrow and furrows framing genital and anal opening. Epimeral setation 3-1-2-1. Genital setae 3 pairs, short; aggenital setae 1 pair, adanal setae short, 3 pairs (ad1-3), anal setae 2 pairs (an1-2).

Legs. Porose areas on the same leg segments and positions as in adults. Chaetome and solenidia see table 3.

Figures

FIGURE 11. Alismobates pseudoreticulatus sp. nov. adult. A) dorsal view. B) ventral view. C) lateral view.

FIGURE 12. A. pseudoreticulatus sp. nov. adult left legs, antiaxial view. A) leg I. B) leg II. C) leg III. D) leg IV.

FIGURE 13. A. pseudoreticulatus sp. nov. tritonymph. A) dorsal view. B) ventral view.