Litoribates floridae, Pfingstl & Lienhard & Baumann, 2019

Pfingstl, Tobias, Lienhard, Andrea & Baumann, Julia, 2019, New and cryptic species of intertidal mites (Acari, Oribatida) from the Western Caribbean - an integrative approach, International Journal of Acarology 45 (1 - 2), pp. 10-25 : 13-15

Litoribates floridae sp. nov.

Type material/locality

Holotype: adult female, Florida U.S. A, Florida Keys , Islamorada (FL_08), leaf litter under red mangrove ( Rhizophora mangle ); 13 February 2017, coll. T. Pfingstl and A. Lienhard, preserved in ethanol, deposited at the Naturhistorisches Museum Wien, Vienna. Four paratypes from the same sample, deposited in the collections of the US National Museum and the Senckenberg Museum für Naturkunde Görlitz, respectively. Additional non-type specimens are stored in the collections of the Institute of Biology, University of Graz.

Etymology

The specific epithet is a noun in the genitive case, referring to Florida, the type locality of this species.

Diagnosis

Adult instar brown sclerotized. Length 336 – 375 µm, width 231 – 259 µm. Notogaster rounded, almost circular in dorsal view. Slender lamellar ridges anteriorly converging. Sensillus slightly clavate and spinose at tip. Cerotegument finely granular, obviously larger granules in humeral areas. Irregular longitudinal cuticular ridges flanking lenticulus, conspicuous cuticular pattern absent in other notogastral areas. Fourteen pairs of setiform, notogastral setae. Epimeral setation 3-1-2-2, setae 1b and 3b the longest.

Remarks

Presently, there are only three species of this genus known. Litoribates floridae can be easily distinguished from the Pacific L. caelestis by the absence of the obvious reticulate cuticular surface pattern present in the latter and its larger size (mean length 360 µm vs. 322 µm). It is morphologically very similar with L. bonairensis but has several irregular longitudinal cuticular ridges in the humeral region that are either absent or only faintly developed in the latter species.

Description

Measurements. Females (N = 9), length: 336 – 375 μm (mean 368 μm), width: 240 – 259 μm (mean 249 μm); males (N = 7), length: 350 – 363 μm (mean 357 μm), width: 231 – 246 μm (mean 238 μm).

Integument. Colour dark brown.

Prodorsum. ( Figures 3 (a) and 4(a)) Cerotegument finely granular, larger granules next to anterior notogastral border and bothridia. Rostrum nearly triangular in dorsal view, projecting anteroventrally in lateral view; demarcated from remainder of prodorsum by faint transverse ridge. Pair of converging, slender lamellar ridges in slightly lateral position, reaching from bothridium to lamellar seta. Rostral seta (ro) robust, setiform, smooth (approx. 30 µm). Lamellar seta (le) setiform, short (approx. 15 µm), and smooth. Interlamellar seta (in) setiform (approx. 20 µm), exobothridial seta (ex) minute. Bothridium hardly protruding, borders not clearly defined; orifice narrow and circular. Sensillus (ss) long (approx. 75 µm), slightly bent caudally, slightly clavate, and spinose at the tip.

Gnathosoma . Typical for the genus. Distal part of rutellum developed as thin triangular membrane, slightly curved inward with longitudinal incision ( Figure 5 (a)). Setae a and m long (approx. 30 µm), robust, and smooth. Mentum regular, seta h setiform, thin (approx. 20 µm). Palp setation 0-2-1-3-8 (solenidion not included), trochanter very short, femur by far longest segment, genu, tibia, and tarsus of almost equal length ( Figure 5 (b)). Chelicera with mobile digit darker sclerotized; distinct teeth interlocking. Träghård ’ s organ (tg) slender blunt finger-like oncophysis. Seta cha and chb dorsally slightly pectinate both of the same length (approx. 25 µm) ( Figure 5 (c)).

Gastronotic region. ( Figures 3 (a) and 4(a)) Conspicuously rounded in dorsal view, convex in lateral view; anterior notogastral margin distinct, forming a slightly overhanging bulge in area of lenticulus. Lenticulus slightly trapezoid with slightly irregular borders. Cerotegument finely granular, obviously larger granules in humeral areas next to lenticulus. Irregular short longitudinal cuticular ridges flanking lenticulus. Several small circular light spots posterior to seta c 1, representing sigilla of dorsoventral muscles. Fourteen pairs of setiform notogastral setae (8 – 16 µm), c 1 - 2, da, dm, dp, la, lm, lp, h 1 - 3, p 1-3; seta c 3 absent. Five pairs of notogastral lyrifissures present; ia laterad of seta c 2, hardly discernible due to strong cerotegumental granulation and cuticular ornamentation; im laterad of seta lm; ih laterad and anterior to h 3; lyrifissures ip and ips laterally of seta p 3 and p 2, respectively. Orifice of opisthonotal gland (gla) laterad, between seta lm and lp.

Lateral aspect. ( Figures 3 (c) and 4(c)) Cerotegument mostly finely granular, larger granules on pedotectum I and in areas surrounding acetabula. Pedotectum I small rounded, slightly projecting. Pedotectum II absent. Discidium present, not conspicuously expressed. Van der Hammen ’ s organ present; typical for the genus (for details, see Pfingstl and Schatz 2017).

Podosoma and venter. ( Figures 3 (b) and 4(b)) Cerotegument finely granular. Epimeral setation 3-1-2-2, all setae setiform and smooth. Setae 1b and 3b longest (approx. 18 µm), others shorter (10 µm). Internal borders of all epimera well visible. Median longitudinal small ridge on epimeron I, other sternal surface lines slightly protruding with small indentations at each transition from one epimeral segment to the other. Genital and anal opening closely adjacent, both surrounded by slightly darker cuticle. Rounded genital plates with four pairs of fine setae (approx. 10 µm). One pair of setiform aggenital setae ag. Anal valves strongly triangular. Outer part of preanal organ rectangular with rounded edges, inner part shaped like transverse bar. Two pairs of short anal setae, an 1-2 (approx. 10 µm). Three pairs of short adanal setae, ad 1-3 (approx. 8 µm). Lyrifissure iad flanking posterior third of anal plates.

Legs. ( Figure 6 ) Monodactylous and slender. Long, strong hook-like claws, with inconspicuous dorsal dentition. Cerotegument generally finely granular, larger granules only on distal third of all femora. Trochanter III and IV with obvious dorsal spur. All genua with ventral transversal ridge. Large elongate porose areas on ventral paraxial side of femora I and II and on paraxial dorsal aspect of femora III and IV. Kidney-shaped porose areas on paraxial dorsal aspect of trochanters III and IV. Dorsal seta d on all femora slightly thickened and barbed on outer curvature. Lateral setae of femora and genua I and II blunt, short, broadened, and slightly serrate. Ventral setae of all tibiae and tarsi long and slightly serrate ventrally. Tibia IV with two setae. Solenidia φ 1-2 on tibia I borne on vaguely delimited mound. Chaetome and solenidia given in Table 2 .

Figures

Figure 3. Litoribates floridae sp. nov. adult (a) dorsal view; (b) ventral view, distal leg segments omitted; (c) lateral view.

Figure 5. Litoribates floridae sp. nov. adult mouthparts (a) right rutellum, ventral view; (b) left pedipalp, paraxial view; (c) left chelicera, antiaxial view.

Figure 6. Litoribates floridae sp. nov. adult left legs, antiaxial view (a) leg I; (b) leg II; (c) leg III; (d) leg IV.