Ancestral state reconstruction reveals multiple independent evolution of diagnostic morphological characters in the "Higher Oribatida" (Acari), conflicting with current classification schemes

<p>Abstract</p> <p>Background</p> <p>The use of molecular genetic data in phylogenetic systematics has revolutionized this field of research in that several taxonomic groupings defined by traditional taxonomic approaches have been rejected by molecular data. The taxonomic classification of the oribatid mite group Circumdehiscentiae ("Higher Oribatida") is largely based on morphological characters and several different classification schemes, all based upon the validity of diagnostic morphological characters, have been proposed by various authors. The aims of this study were to test the appropriateness of the current taxonomic classification schemes for the Circumdehiscentiae and to trace the evolution of the main diagnostic traits (the four nymphal traits scalps, centrodorsal setae, sclerits and wrinkled cuticle plus octotaxic system and pteromorphs both in adults) on the basis of a molecular phylogenetic hypothesis by means of parsimony, likelihood and Bayesian approaches.</p> <p>Results</p> <p>The molecular phylogeny based on three nuclear markers (28S rDNA, <it>ef-1α</it>, <it>hsp82</it>) revealed considerable discrepancies to the traditional classification of the five "circumdehiscent" subdivisions, suggesting paraphyly of the three families Scutoverticidae, Ameronothridae, Cymbaeremaeidae and also of the genus <it>Achipteria</it>. Ancestral state reconstructions of six common diagnostic characters and statistical evaluation of alternative phylogenetic hypotheses also partially rejected the current morphology-based classification and suggested multiple convergent evolution (both gain and loss) of some traits, after a period of rapid cladogenesis, rendering several subgroups paraphyletic.</p> <p>Conclusions</p> <p>Phylogenetic studies revealed non-monophyly of three families and one genus as a result of a lack of adequate synapomorphic morphological characters, calling for further detailed investigations in a framework of integrative taxonomy. Character histories of six morphological traits indicate that their evolution followed a rather complex pattern of multiple independent gains (and losses). Thus, the observed pattern largely conflicts with current morphological classifications of the Circumdehiscentiae, suggesting that the current taxonomic classification schemes are not appropriate, apart from a recently proposed subdivision into 24 superfamilies.</p

The intertidal Fortuyniidae (Acari: Oribatida): new species, morphological diversity, ecology and biogeography

Pfingstl, Tobias (2015): The intertidal Fortuyniidae (Acari: Oribatida): new species, morphological diversity, ecology and biogeography. Zootaxa 3957 (4): 351-382, DOI: http://dx.doi.org/10.11646/zootaxa.3957.4.

Revealing the diversity of a once small taxon: the genus Selenoribates (Acari, Oribatida, Selenoribatidae)

Three new intertidal oribatid species, Selenoribates elegans sp. n., Selenoribates quasimodo sp. n. and Selenoribates satanicus sp. n. are described from the archipelago of Bermuda. Selenoribates elegans sp. n. is characterized by its slender body shape, S. quasimodo sp. n. possesses a hunchback in lateral view and S. satanicus sp. n. exhibits two horn-like projections on its anterior gastronotic region. Based on these new findings, the number of Selenoribates species doubled at once and the distribution of this genus, formerly limited to the Mediterranean and the Red Sea, includes now occurrences in the Atlantic and Indo-pacific Ocean as well. The morphology of S. quasimodo sp. n. and S. satanicus sp. n. deviates conspicuously from the other known members of Selenoribates, thus indicating that not only the number of species but also the anatomy of this genus is more diverse than formerly supposed. Nymphs of S. quasimodo sp. n. show an interesting case of ontogenetic neotrichy, with gastronotic setae being duplicated with each moult

New littoral mite species (Acari, Oribatida, Fortuyniidae) from the Galápagos archipelago, with ecological and zoogeographical considerations

Pfingstl, Tobias, Schatz, Heinrich (2017): New littoral mite species (Acari, Oribatida, Fortuyniidae) from the Galápagos archipelago, with ecological and zoogeographical considerations. Zootaxa 4244 (1): 39-64, DOI: https://doi.org/10.11646/zootaxa.4244.1.

Alismobates inexpectatus Pfingstl & Schuster, 2012, sp. nov.

Alismobates inexpectatus sp. nov. Type material - Holotype: female, Bermuda, Tobacco Bay, upper intertidal zone, rocks covered with mats of algae; 17 /07/ 1981, R. Schuster leg. (Be- 108 =sample number in the collection R.S.). Paratypes: 4 females and 4 males, same locality as holotype. Deposition of holo- and paratypes: Senckenberg Museum für Naturkunde Görlitz, Germany (Collection Nr. 81 / 47300). Etymology. About 30 years ago, when he discovered F. atlantica on Bermuda (Krisper & Schuster 2008), Schuster also collected specimens of another unknown species. He regarded these specimens to be individuals of a new selenoribatid species but did not pay further attention to it as he focused on the sexually dimorphic F. atlantica. Decades later, when Schuster was told that he had found at that time a new Alismobates species, he was very surprised. He did not expect a further fortuyniid species to be present on the archipelago of Bermuda, therefore the name refers to the Latin word “ inexpectatus ” meaning unexpected. Diagnosis. Dark brown sclerotized mites. Habitus typical for the genus Alismobates. Average length 366 µm, mean width 246 µm. Notogaster oval in shape. No conspicuous sexual dimorphism in notogastral setation, porose areas, anogenital region and features of the legs; there is only the common sexual dimorphism in overall body size, with females being generally slightly larger. Van der Hammen’s Organ well developed, but diverging from Fortuynia typical pattern. Sensillus clavate, spinose. One pair of large cuticular ridges in position of prodorsal lamellae. Interlamellar setae minute. Lenticulus large, variable in shape. Areas flanking lenticulus conspicuously granular. Fourteen pairs of short and simple, notogastral setae, associated with small porose areas. Four pairs of single pores medially on notogaster and one pair of four semicircular grouped pores on posterior gastronotic region. Epimeral setation 3 - 1-2 - 2. Four pairs of genital setae. One pair of aggenital setae. Three pairs of adanal setae. Two pairs of anal setae. Legs monodactylous with large claw. Porose areas on trochanters III and IV and all femora. Leg setation (chaetome, solenidia): Leg I 0- 4 - 2-3 - 18, 1 - 2 - 2; leg II 0- 4 - 2-3 - 15, 1 - 1 - 1; leg III 1-3 - 1-3 - 15, 1- 1 -0; leg IV 1-2 - 2-3 - 12, 0-1 -0. Juveniles plicate with large foveate centrodorsal plate. Description of adult. Females (N= 17), length: 360–391 μm (mean 375 μm), width: 240–253 µm (mean 249 µm); males (N= 21), length: 347–372 μm (mean 356 μm), width: 235–249 µm (mean 242 µm) Integument. Colour ranging from dark brown to nearly black. Cuticle appears shiny, but finely granulate under dissecting microscope. Prodorsum. Cerotegument finely granular, larger granules next to anterior notogastral border. Rostrum rounded in dorsal view, but slightly projecting anteroventrally in lateral view. Whole rostrum clearly demarcated from remainder of prodorsum by an obvious transverse ridge. A pair of two slightly converging, thickened and broad cuticular ridges in position of prodorsal lamellae. Borders of these ridges shaped irregularly except for lateral aspects showing a clear straight edge. A further single and nearly elliptic median area of thickened cuticle between lamellar setae. Rostral setae (ro) strong, simple and dorsally slightly barbed. Lamellar setae (le) simple, short and smooth. Interlamellar setae (in) minute. One pair of very short and fine exobothridial setae (ex). Bothridia cup-like with a lateral incision, strongly projecting, orifice narrow and circular. Sensilla of normal length, slightly clavate, distally spinose. An elliptic plate-like cuticular ridge dorsally adjacent to base of bothridium, covering dorsosejugal suture over a short distance. Gnathosoma. Pedipalp (Figure 1 A) pentamerous 0-2 - 1-3 - 9 (including solenidion), trochanter very short, femur by far longest segment, genu, tibia and tarsus of almost equal length. Solenidion ω on palptarsus erect, not associated with eupathidium acm. Chelicerae (Figure 1 B) chelate, mobile digit slightly darker sclerotized, with three small, blunt but distinct teeth, whereas from frontal view most distal teeth split into two symmetrical teeth; fixed digit with two teeth, all teeth interlocking. Large lateral porose area from middle of chelicerae to joint of digits. Seta cha and chb of approximately the same length, both dorsally slightly pectinate. Trachea reaching into anterior part of chelicera. Gena well sclerotized but finely porose. Distal part of rutellum developed as thin triangular slightly curved inward membrane (Figure 1 C). Seta a and m long, robust and smooth. Mentum regular, seta h simple, thin and of normal length. Gastronotic region (Figure 2 A). Conspicuously rounded, anterior notogastral margin distinct. Cerotegument mainly finely granular, but showing conspicuously larger granules in areas flanking median light spot. Lenticulus developed as large anterior median light spot with irregular borders. Shape of lenticulus highly variable, from rectangular to square. Fourteen pairs of relatively short and simple notogastral setae, c 1-2, da, dm, dp, la, lm, lp, h 1-3, p 1- 3; seta c 3 absent. Small circular porose areas associated with bases of all notogastral setae. Additionally four pairs of single pores arranged in two median parallel rows. First pair posterior c 1, second posterior da, third posterior dm and fourth posterior dp. Next to seta h 2 a series of four pores arranged in a semicircular median row. No difference in the arrangement of these pores between the sexes. Five pairs of notogastral lyrifissures present; ia next to seta c 2 close and rectangular to anterior notogastral border; im slightly anterior and laterad of seta lm; ih between seta h 2 and h 1; lyrifissures ip and ips laterally of seta p 3 and p 2 respectively. Orifice of opisthonotal gland (gla) laterally between setae lm and lp. Lateral aspect (Figure 2 B). Cerotegument generally finely granular, larger granules in areas surrounding acetabula. Tutorium present, anterior part a ventrad curved bulge, posterior part fused with prodorsal lateral ridge. Pedotectum I weakly developed, only slightly projecting. Pedotectum II a minute plate-like ridge. Discidium not conspicuously expressed. Van der Hammen’s Organ modified, consisting of a system of four combined parts (Figure 3 A): First and major part (1), a large canal connected with the outside only by a small slit, starts at the lateral part of dorsosejugal suture, passes posterior of bothridium and runs ventrad to area between acetabulum II and III, where it diverges into an anterior and posterior branch. Second and smallest part (2) consisting of a short channel connecting lateral incision of bothridium with the above mentioned main canal. Third part (3) is the anterior lateroventral branch passing acetabulum II posteriorly and curving on the ventral side anteriorly into a distinct longitudinal canal reaching ventral tip of pedotectum I where it opens in acetabulum I. Fourth part (4) is the posterior branch, represented by a deepened broad groove running caudad passing dorsally acetabulum III and ending at acetabulum IV. Stigma of acetabular trachea III situated in ramification of part one, three and four (Figure 4). Ventral region of idiosoma (Figure 2 C). Cerotegument in sternal region finely granular, larger granules laterally next to acetabula and on most posterior part of ventral plate. Epimeral setation 3 - 1-2 - 2, all setae simple and smooth. Seta 1 b about a third longer than other setae. Seta 1 c close to pedotectum I, laterad of ventral longitudinal channel of van der Hammen’s Organ. Internal borders of all epimera well visible, sternal apodemes II, III and IV well developed. Genital and anal opening closely adjacent, both surrounded by strongly sclerotized cuticle. Rounded genital plates with four pairs of fine and simple genital setae. First and longest pair near medial margin of valves, second and fourth pair median on plates and third pair close to lateral margin of valves. Laterad of genital opening a circular spot of thickened cuticle. One pair of simple aggenital setae ag. Anal valves nearly triangular, median margins slightly overlapping. Outer part of preanal organ triangular with rounded edges, inner part shaped like a broad transverse bar. Two pairs of short and simple anal setae, an 1-2, arranged in a longitudinal row. Three pairs of short and simple adanal setae, ad 3 laterad of anterior third of anal plates, ad 2 near posterior third of anal valves and ad 1 posterior of anal opening. Lyrifissure iad orientated longitudinally and flanking posterior third of anal plates. Thickened cuticle on posterior part of ventral plate, clearly delimitated from anterior thinner cuticle by two concave symmetric arches next to anal opening. Legs (Figure 5). Monodactylous. Long, strong hook-like claws. 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 only slightly darker than distal part. Femora without ventral carina. Cerotegument generally finely granular, larger granules only on distal third of all femora. All tarsi with proximal lyrifissure. Large irregularly shaped porose areas on ventral paraxial side of femur I and II, porose areas on proximal part of femora III and IV divided in a large dorsal and a smaller ventral part, kidney-shaped porose areas on paraxial dorsal aspect of trochanters III and IV. Dorsal seta d on all femora slightly thickened and dorsally serrate. Lateral setae of all genua short, broadened and slightly serrate. Ventral setae of all tibiae and tarsi, long and ventrally strongly serrate. Solenidia &straightphi; 1-2 on tibia I borne on small apophysis. Chaetome and solenidia see table 1. Common features of juvenile stages. Apheredermous. Colour dark brown. Integument plicate and soft, except for centrodorsal plate (Figure 6). Prodorsum triangular, anterior part finely granular, rostrum rounded. Rostral (ro) and lamellar setae (le) short and simple. One pair of short exobothridial setae (ex) and minute interlamellar setae (in). Sensilla of normal length clavate and distally spinose. Bothridia cup-like, laterally opened. Medially on posterior border of prodorsum groups of distinct pores leading into fine tracheal tubes (Figure 7 A); these structures are difficult to detect as in dorsal view they are hidden beneath anterior folds of gastronotic region. Gnathosoma no obvious differences to adult stage. Hysterosoma slightly convex. Hysterosomal cupules not traceable in any stage. Large, foveate and stronger sclerotized centrodorsal plate bearing all notogastral setae, except for c 1-3 in all stages and seta h 2 in the larval stage. Lateral borders of plate straight, anterior border slightly convex, posterior border strongly convex. In nymphal stages posterior part of this plate showing a median lesser sclerotized and slightly concave conspicuous area without foveae resembling an inverted Y. Two parallel longitudinal rows of slightly darker pigmented spots on centrodorsal plate, whereas these spots are hardly discernable in most of the specimens. Large folds framing centrodorsal plate completely, showing fine granular surface. Within the lateral folds at least four hardly discernable pores on a level with acetabulum III and a series of further pores (number is hard to determine) aligned longitudinally. Orifice of opisthonotal gland (gla) located in posterior third of lateral folds. Small circular or elliptic porose areas associated with bases of all notogastral setae. Ventral sejugal suture developed as distinct furrow, posterior border medially opened over a short distance. Integument surrounding anal area folded. In nymphal stages no distinct genital sclerites developed, genital opening only a thin longitudinal slit, inner margins showing small granules. Anterior to genital area a slightly rostrad arched large furrow showing conspicuous granules. Nymphs with two distinct slightly curved furrows posterior of genital area, reaching from acetabulum IV to anterior end of anal opening, where they pass into distinct folds framing anal orifice. Within these furrows posterior of genital opening, fine cuticular pores. Anal area conspicuously finely granular. Legs monodactylous. Dorsal setae of tibiae and genua absent when respective solenidion present. Solenidia on tibia I borne on small apophysis. Large porose areas on ventral paraxial side of femora I and II and on dorsal paraxial side on femora III and IV. Circular porose areas on paraxial dorsal side of trochanters III and IV. Instars Trochanter Femur Genu Tibia Tarsus Chaetome Solenidia Leg I larva - d, bv´´ (l), σ (l), v´,&straightphi; 1 (pl), (pv), s, (a), (u), (p), (tc), (ft),?, ω 1 0-2 - 2-3 - 16 1 - 1 - 1 protonymph - l ´- - ω 2 0-3 - 2-3 - 16 1 - 1-2 deutonymph - l ´´ - &straightphi; 2 - 0-4 - 2-3 - 16 1-2 - 2 tritonymph - - - - (it) 0-4 - 2-3 - 18 1-2 - 2 adult - - - - - 0-4 - 2-3 - 18 1-2 - 2 Leg II larva - d, bv´´ (l), σ l´, v´, &straightphi; (pv), s, (a), (u), (p), (tc), (ft), ω 0-2 - 2 - 2- 13 1 - 1 - 1 protonymph - l ´- - - 0-3 - 2 - 2- 13 1 - 1 - 1 deutonymph - l ´´ - - - 0-4 - 2 - 2- 13 1 - 1 - 1 tritonymph - - - l ´´ (it) 0-4 - 2-3 - 15 1 - 1 - 1 adult - - - - - 0-4 - 2-3 - 15 1 - 1 - 1 Leg III larva - d, ev´l´, σ v´, &straightphi; (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 - - - - (it) 1-2 - 1 - 1-15 1 - 1 -0 adult - l ´- (l) - 1-3 - 1-3 - 15 1 - 1 -0 Leg IV protonymph - - - - (pv), (u), (p), ft´´ 0-0-0- 0-7 0-0-0 deutonymph - d, ev´d, l´v´, &straightphi; s, (a), (tc) 0- 2 - 2 - 1-12 0-1 -0 tritonymph v ´- - - - 1-2 - 2 - 1-12 0-1 -0 adult - - - (l) - 1-2 - 2-3 - 12 0-1 -0 Larva. Length (N= 10): 160–197 μm (mean 176 μm) Gastronotic region (Figure 8 A). Eleven pairs of slightly thickened and slightly serrate notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-2; h 3 absent. Conspicuous transverse ridge on centrodorsal plate passing posterior line of setae dm and lm. Ventral region of idiosoma (Figure 8 B). Epimeral setation 3 - 1-2, epimeral setae of normal length, thin and simple, except for seta 1 c shaped valve-like protecting Claparède organ. Cuticle framing the latter anteromedially thickened and slightly projecting. Integument posterior of ventral sejugal furrow with a few inconspicuous transversal folds. Legs. Setation and solenidia see table 1. Protonymph. Length (N= 24): 200–262 μm (mean 237 μm) Gastronotic region (Figures 8 C, 9). Fifteen pairs of notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-3 and p 1-3, all setae lesser thickened from this stage. Transverse ridge on centrodorsal plate passing posterior line of setae dm and lm absent from this stage. Ventral region of idiosoma (Figure 8 D). Epimeral setation 3 - 1-2 - 1. Seta 1 c developed as normal seta, next to trochanter I, seta 4 a close to trochanter IV. One pair of short genital setae. Aggenital setae absent. Legs (Figure 10). Chaetome and solenidia see table 1. Deutonymph. Length (N= 31): 262–311 μm (mean 287 μm). Gastronotic region (Figure 11 A). Fifteen pairs of notogastral setae, same positions and shapes as in protonymph. Ventral region of idiosoma (Figure 11 B). Epimeral setation 3 - 1-2 - 1. Two pairs of short genital setae arranged in a longitudinal row. One pair of simple and short aggenital setae ag. Three pairs of adanal setae ad 1-3 flanking anal valves. Legs (Figure 12). Chaetome and solenidia see table 1. Tritonymph. Length (N= 16): 329–386 μm (mean 363 μm) Gastronotic region (Figure 11 C). Fifteen pairs of notogastral setae, no difference to deutonymph. Ventral region of idiosoma (Figure 11 D). Epimeral setation 3 - 1-2 - 2, seta 4 b median on epimeral plate IV. Three pairs of short genital setae in a longitudinal row. One pair aggenital setae ag. Three pairs of adanal setae ad 1- 3. Two pairs of anal setae an 1-2, sometimes asymmetrical variation with three setae developed on only one valve (as shown in Figure 11 D). Legs. Chaetome and solenidia see table 1.Published as part of Pfingstl, Tobias & Schuster, Reinhart, 2012, First record of the littoral genus Alismobates (Acari: Oribatida) from the Atlantic ocean, with a redefinition of the family Fortuyniidae based on adult and juvenile morphology, pp. 1-33 in Zootaxa 3301 on pages 3-11, DOI: 10.5281/zenodo.21014

Fortuynia atlantica

Juveniles of Fortuynia atlantica – common features Apheredermous. Colour black, cuticle shiny appears polished. Majority of integument thick sclerotized, except for lateral folds surrounding centrodorsal plate (Figure 13). Due to their dark coloration nymphs showing generally a strong similarity to adult specimens under dissecting microscope. Gastronotic region strongly dorsoventrally flattened, whole body streamlined shaped. Prodorsum triangular. Rostrum rounded demarcated from remainder of prodorsum by an inconspicuous transverse ridge. Rostral setae (ro) long, thin and smooth. Lamellar setae (le) simple, smooth, half the length of (ro). Exobothridial setae (ex) minute and interlamellar setae (in) only vestigial. Sensilla short, capitate and overall smooth. Bothridia cup-like, narrow orifice with lateral incision. Medially on posterior border of prodorsum two paired groups of distinct pores leading into tracheal tubes (Figure 7 B); in dorsal view covered by anterior folds of gastronotic region. Gnathosoma no obvious differences to adult stage. Pedipalp pentamerous 0-2 - 1-3 - 9 (solenidion included). Rutella broad, with membranous margin. Setae a and m thin, simple of normal length. Seta h long, smooth and spiniform. Lateral posterior borders of mentum tip-like elongated. Hysterosoma slightly convex. Hysterosomal cupules present but difficult to trace in any stage. Large centrodorsal plate finely punctate and stronger sclerotized, bearing all notogastral setae, except for c 1-3 in all stages and seta h 2 in the larval stage. Lateral borders of plate straight, anterior border slightly convex, posterior border strongly convex. In nymphal stages posterior part of centrodorsal plate showing a median lesser sclerotized smooth area resembling an inverted Y, whereas longitudinal line long reaching anterior third of plate. Large folds surrounding centrodorsal plate. Within lateral folds a series of longitudinally arranged fine but distinct pores, each turning into fine tracheal internal tubes (Figure 14). Orifice of opisthonotal gland (gla) in posterior half of lateral folds. Small porose areas associated with bases of notogastral setae. A series of large darker spots arranged in two longitudinal rows, in anterior part of centrodorsal plate spots aligned transversally connecting longitudinal rows; these darker areas generally difficult to trace. Ventrosejugal suture developed as distinct furrow, resembling medially a broad V. Nymphs with no distinct genital valves, genital orifice a longitudinal slit, inner margins with conspicuous granules. Anterior to genital opening a slightly rostrad curved canal-like fold. Posterior to anal region caudad arched furrows, along these folds singular fine pores (Figure 15). Legs monodactylous. Integument showing same pattern as in adults, trochanters dark, heavily sclerotized, proximal third of femora light, remainder dark, genua dark, tibiae light, proximal part of tarsi dark and distal parts light. Dorsal setae of tibiae and genua absent when respective solenidion present. Solenidia on tibia I inserting on small apophysis. Large porose areas on ventral paraxial side of femora I and II and on dorsal paraxial side on femora III and IV. Circular or elliptic porose areas on paraxial dorsal side of trochanters III and IV. Tarsal lyrifissure already observable in all juvenile stages. Larva. Length (N= 3): 226–235 μm (mean 231 μm) Gastronotic region (Figure 16 A). Eleven pairs of strong, smooth and spiniform notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-2; h 3 absent. All setae long, except for seta dm showing normal length, setae c 1, la, lm and dp a third longer than remaining setae. Conspicuous transverse ridge on centrodorsal plate passing posterior line of setae dm and lm. Ventral region of idiosoma (Figure 16 B). Epimeral setation 3 - 1-2, seta 1 c shaped valve-like protecting Claparède organ. Cuticle surrounding Claparède organ anteromedially strongly sclerotized, developed as protruding protective ridge. A transverse fold anterior of anal orifice. Legs. Setation and solenidia see table 2. Protonymph. Length (N= 17): 258–306 μm (mean 287 μm) Gastronotic region (Figure 16 C, 17). Fifteen pairs of notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-3 and p 1-3. Seta c 1 and h 1 longest, dm, dp and h 3 shortest. Transverse ridge on centrodorsal plate passing posterior line of setae dm and lm, absent from this stage. Ventral region of idiosoma (Figure 16 D). Epimeral setation 3 - 1-2 - 1. Seta 1 c ordinary seta, close to trochanter I, seta 4 a near trochanter IV. One pair of genital setae, located in the middle of genital area. Aggenital setae absent. Setae p 3 and p 2 flanking anal opening. Legs (Figure 18). Chaetome and solenidia see table 2. Instars Trochanter Femur Genu Tibia Tarsus Chaetome Solenidia Leg I larva - d, bv´´ (l), σ (l), v´, &straightphi; 1 (pl), (pv), s, (a), (u), (p), (tc), (ft),?, ω 1 0-2 - 2-3 - 16 1 - 1 - 1 protonymph - - - - ω 2 0-2 - 2-3 - 16 1 - 1-2 deutonymph - l ´- j 2 - 0-3 - 2-3 - 16 1-2 - 2 tritonymph - l ´´ - - (it) 0-4 - 2-3 - 18 1-2 - 2 adult* v ´´ - - - - 1-4 - 2-3 - 18 1-2 - 2 Leg II larva - d, bv´´ (l), σ l´, v´, &straightphi; (pv), s, (a), (u), (p), (tc), (ft), ω 0-2 - 2 - 2- 13 1 - 1 - 1 protonymph - - - - - 0-2 - 2 - 2- 13 1 - 1 - 1 deutonymph - l ´´ - - - 0-3 - 2 - 2- 13 1 - 1 - 1 tritonymph - l ´- - (it) 0-4 - 2 - 2- 15 1 - 1 - 1 adult * v ´´ - - l ´´ - 1-4 - 2-3 - 15 1 - 1 - 1 Leg III larva - d, bv´l´, σ v´,&straightphi; (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 ´- l ´(it) 1-3 - 1-2 - 15 1 - 1 -0 adult* l ´- - l ´´ - 2-3 - 1-3 - 15 1 - 1 -0 Leg IV protonymph - - - - (pv), (u), (p), ft´ 0-0-0- 0-7 0-0-0 deutonymph - d, bv´d, l´v´, &straightphi; s, (a), (tc) 0- 2 - 2 - 1-12 0-1 -0 tritonymph v ´- - l ´- 1-2 - 2 - 2-12 0-1 -0 adult* - - - l ´´ ft´´1-2 - 2-3 - 13 0-1 -0 Deutonymph. Length (N= 22): 306–369 μm (mean 341 μm) Gastronotic region (Figure 19 A). Fifteen pairs of notogastral setae, same positions and shapes as in protonymph. Ventral region of idiosoma (Figure 19 B). Epimeral setation 3 - 1-2 - 2, seta 4 b median on epimeral plate IV. Two pairs of genital setae in a longitudinal row. One pair of simple and short aggenital setae ag laterad of posterior genital setae. Three pairs of adanal setae ad 1-3 flanking anal valves. Two pairs of vestiges on anal plates. Legs (Figure 20). Chaetome and solenidia see table 2. Tritonymph. Length (N= 15): 395–431 μm (mean 415 μm) Gastronotic region (Figure 19 C). Fifteen pairs of notogastral setae, no difference to deutonymph. Ventral region of idiosoma (Figure 19 D). Epimeral setation 3 - 1-3 - 2, seta 3 c next to trochanter III. Four pairs of short genital setae arranged in two longitudinal semicircles. One pair of aggenital setae ag. Three pairs of adanal setae ad 1-3 flanking anal opening, whereas ad 1 twice as long as others. Two pairs of anal setae an 1-2. Legs. Chaetome and solenidia see table 2.Published as part of Pfingstl, Tobias & Schuster, Reinhart, 2012, First record of the littoral genus Alismobates (Acari: Oribatida) from the Atlantic ocean, with a redefinition of the family Fortuyniidae based on adult and juvenile morphology, pp. 1-33 in Zootaxa 3301 on pages 11-18, DOI: 10.5281/zenodo.21014

Fortuynia

Genus Fortuynia van der Hammen, 1960 Medium sized (400 µm– 600 µm body length) dark sclerotized intertidal mites. Interlamellar setae vestigial or minute. Lamellar ridges developed as cuticular channels or completely absent. Translamella strongly reduced or absent. Sensillus short, clavate, smooth or spinose. Tutorium absent. Van der Hammen’s organ present, typical for the genus. Pedotecta present, weakly developed. Lenticulus present or absent. Notogaster with 14 pairs of setae, sometimes c 3 vestigial. Genital setae 5 pairs.Published as part of Pfingstl, Tobias & Schuster, Reinhart, 2012, First record of the littoral genus Alismobates (Acari: Oribatida) from the Atlantic ocean, with a redefinition of the family Fortuyniidae based on adult and juvenile morphology, pp. 1-33 in Zootaxa 3301 on page 11, DOI: 10.5281/zenodo.21014

Fortuyniidae

Biogeography of Fortuyniidae Schuster (1983, 1989) already supposed a transoceanic distribution of the family Fortuyniidae and several years later his assumption was finally confirmed when F. atlantica from the coasts of Bermuda was officially described (Krisper & Schuster 2008). Adding this last Atlantic record to the other known occurrences on coasts of the Indian and Pacific Ocean (Schuster 1989; Bayartogtokh et al. 2009), the diverse genus Fortuynia now exhibits a worldwide pan- and subtropic distribution. (Figure 21) The less species rich genus Alismobates and the monotypic Circellobates, on the other hand, were found only in a very limited geographic range of the East China Sea, with records of A. rotundus and C. venustus from Hong Kong (Luxton 1992) and A. reticulatus from Hong Kong (Luxton 1992) and the Japanese Ryukyu Islands (Karasawa & Hiji 2004; Karasawa & Aoki 2005). The present discovery of a third Alismobates species on the shores of the Atlantic archipelago of Bermuda expands the geographic distribution of this genus enormously but leaves a large gap in the eastern part of the Pacific Ocean. Quite possibly further islands of the Pacific region, the Pacific as well as the Atlantic coastline of Central America and several Caribbean Islands may have been successfully colonized by this taxon but insufficient sampling within these areas may be responsible for the apparently discontinuous distribution pattern. At present the new species A. inexpectatus was only recorded from the archipelago of Bermuda, but here it can be found at many localities along the coastline (Figure 22) inhabiting predominantly mats of the alga Bostrychia tenella growing on rocks in the littoral zone. Although this species, as well as F. atlantica, may be restricted to Bermuda, their endemic status should only be regarded as provisional until the intertidal mite fauna of Central American coasts and the Caribbean Sea are investigated in a more comprehensive way and further distributions of these species can be definitely excluded. (A sampling excursion to some of these areas will be performed by one of the authors in the near future and is supposed to give further insights into the distribution of these taxa)Published as part of Pfingstl, Tobias & Schuster, Reinhart, 2012, First record of the littoral genus Alismobates (Acari: Oribatida) from the Atlantic ocean, with a redefinition of the family Fortuyniidae based on adult and juvenile morphology, pp. 1-33 in Zootaxa 3301 on page 32, DOI: 10.5281/zenodo.21014

Claw shape variation in oribatid mites of the genera Carabodes and Caleremaeus: exploring the interplay of habitat, ecology and phylogenetics

Background Claws are a commonly observed biological adaptation across a wide range of animal groups. They serve different functions and their link to evolution is challenging to analyze. While there are many studies on the comparative anatomy and morphology of claws in reptiles, birds and several arthropods, knowledge about claws of soil-living oribatid mites, is still limited. Recent research on intertidal oribatid mites has shown that claw shape is strongly correlated with microhabitat and is subject to ecological selective pressures. However, the selective constraints shaping claws in terrestrial oribatid mites are still unknown. Methods In this study, 300 specimens from 12 different species and two genera were examined. Geometric morphometrics were used to quantify claw length and curvature, and to analyze two-dimensional claw shape. In combination with molecular phylogenetic analyses of investigated populations phylogenetic signal was quantified within genera using Blomberg’s K and random replicates. Additionally, ecological information on the investigated species was gathered from previous studies and compiled into tables. Results The claw shapes of Carabodes species vary moderately, with the three species C. reticulatus, C. rugosior and C. tenuis deviating the most from the others. These three species are only found in a small number of habitats, which may require a more specialized claw shape. Our results show that there is a phylogenetic influence on claw shape in Carabodes but not in Caleremaeus. Additionally, habitat specificity and lifestyle were found to have ecological impact on claw shape in both genera. The present results demonstrate that characteristics of the claws of terrestrial oribatid mites are correlated with ecology, but this correlation is apparently weaker than in intertidal oribatid mites that are prone to strong external forces