Rhombognathus cilbizi, Durucan & Paz & Hernández-Teixidor, 2025

Durucan, Furkan, Paz, Juan Carlos De La & Hernández-Teixidor, David, 2025, Description of two new Rhombognathus species (Acari: Trombidiformes: Halacaridae) from Tenerife (Canary Islands), Zootaxa 5636 (3), pp. 587-596 : 589-592

publication ID	https://doi.org/10.11646/zootaxa.5636.3.12
publication LSID	lsid:zoobank.org:pub:89111A50-2CDC-4B75-BB9A-E838AFBB097C
DOI	https://doi.org/10.5281/zenodo.15595302
persistent identifier	https://treatment.plazi.org/id/FF7387AB-FF8A-FFC6-BCAD-FE94FE2B1608
treatment provided by	Plazi
scientific name	Rhombognathus cilbizi
status	sp. nov.

Treatment

Rhombognathus cilbizi sp. nov.

urn:lsid:zoobank.org:act:C6908DC2-0A03-426B-84F2-7928C363C15D

Figures 2a–e View FIGURE 2 ; 3a–d View FIGURE 3 ; Table 1 View TABLE 1

Material examined. Both individuals obtained in La Barranquera GoogleMaps , Rhodomelaceae sp., in the upper eulittoral zone GoogleMaps , 28.53818534, -16.39664927, 1 Sept. 2019. Holotype Female ( FDHAL-25/1 ), undissected and mounted into one slide; GoogleMaps Paratype Male ( FDHAL-25/1 ), undissected and mounted into one slide GoogleMaps .

Etymology. The species is dedicated in honor of Assoc. Prof. Dr. Mehmet Cilbiz (Isparta University of Applied Sciences, Egirdir Fisheries Faculty, Isparta, Türkiye) for his support to the first author’s halacarid research studies in Isparta, Türkiye.

Description. Measurements are presented in Table 1 View TABLE 1 .

Female (holotype). All dorsal plates well separated by striated integument and partly with fine canaliculi. AD wider than long, length/width ratio 0.86. AD anteriorly and posteriorly slightly truncated and medially with canaliculi ( Fig. 2a View FIGURE 2 ). Pair of setae ds- 1, 50 in length, faintly pectinate on AD at 0.39 of AD, slightly longer than following setae which are about 13–17 in length ( Fig. 2 View FIGURE 2 a'). AD and PD separated and distance between AD and PD 63 . Muscle scars arranged along with slightly arched; interval between median scars and anterior margin of AD 50 . OC relatively large, with canaliculi, longer than wide (ratio 0.46) and each with 2 corneae, extending anteriorly to level slightly posterior margin of AD and posteriorly almost but not extending to anterior margin of PD. Pairs of ds- 2 and ds-3 on OC at 0.13 and 0.8, respectively. Glp-2 and glp-3 on OC. Pore canaliculus between 2 gland pores as illustrated ( Fig. 2 View FIGURE 2 a''). PD slender, reaching anteriorly to level slightly anterior to insertion of Leg III. Single pair of setae on PD at 0.10 to anterior of PD. PD laterally scattered with fine canaliculi. Posterior medial part superficially reticulated. Posterior part of PD with 2 faintly elevated ridges. Short adanal setae dorsal on anal papilla.

Ventral plates AE, PE and GP fused in a ventral shield. AP separated by striated cuticle. AE and PE on either side with 1 adjunct setae. Genital area with 5 pairs of pgs. Genital sclerites with 2 pairs of short sgs ( Fig. 2b View FIGURE 2 ); Epimeral region ornamented with several subsurface pores medially ( Fig. 2 View FIGURE 2 b').

Gnathosoma longer than wide. Gnathosoma/idiosoma length 0.3. Rostrum triangular, 25 long; with 2 pairs of maxillary setae. Tectum truncate. Palps 4 segmented. Palps slightly surpassing tip of rostrum. Dorsal seta on P2 long, P3 without seta. P4 with 3 setae in basal whorl ( Fig. 2c View FIGURE 2 ).

Legs shorter than idiosoma. Length of Legs I–IV: 220, 240, 247, 240, respectively. Tarsus I to IV without ventral setae. Leg chaetotaxy ( Figs. 3 View FIGURE 3 a-d) (from trochanter to tarsus) (solenidia, famuli and pas excluded): Leg I, 1, 2, 6, 5, 5, 3; Leg II, 1, 2, 6, 5, 5, 3; Leg III, 1, 2, 3, 3, 5, 4; Leg IV, 0, 2, 3, 3, 5, 3. Delicately pectinate setae on genua and tibiae 1-1-0-0 and 2-2-2-2. Telofemora I-IV with 4/2, 4/2, 3/0 and 2/0 dorsal/ventral setae, Genua I and II with 4/1 dorsal/ventral setae, ventral setae of genua slightly bipectinate, both ventral setae of tibiae stout and slightly bipectinate. Tarsus I with 3 dorsal setae, 1 baciliform dorsolateral solenidion, 1 famulus and paired doublet parambulacral setae. Tarsus II with 3 dorsal setae, 1 baciliform dorsolateral solenidion, and paired pas. Solenidia of Tarsi I and II 10 long. Tarsus III with 4 dorsal setae, the 2 basal ones inserted adjacent, lateral pas spur-like, bipectinate; medial pas seta-like pas. Tarsus IV with 3 dorsal setae, and 2 parambulacral setae; medial pas long and plumose, lateral pas pectinate, short and wide. Carpite of Tarsi I and II 13‒15 long, of Tarsi III and IV 15‒20 long. Claws slender with accessory process, having 8‒10 tines. Median claw and comb not present.

Male. Similar to female in most features ( Figs. 2d, e View FIGURE 2 ). AE, PE, and GP fused in a ventral shield, medially fused to the anal plate with lateral wedges of striated cuticle. Genital area surrounded by 19 branched pgs in trapeziform arrangement including 1 pair of basilar setae 18 branched pgs in trapeziform arrangement. Genital sclerites with two pairs of sgs. Spermatopositor 75 long, 66 wide and extending distinctly beyond GO, a pair of wing-like process (ala) (40 long, 20 wide) on the anterior side ( Fig. 2 View FIGURE 2 e').

Remarks. Rhombognathus cilbizi sp. nov. is characterised by the combination of: AD, OC and PD separated; pair of ds-1 inserted on AD, long (50) and faintly pectinate in female; anterior and posterior parts of AD truncated; Dorsal plates with canaliculi (AD and OC medially, while PD laterally); OC longer than wide and with two setae and two corneae; PD with only a pair of setae; AE, PE and GP combined; AE and PE on either side with 1 adjunct setae; Rostrum shorter than gnathosomal base (ratio 0.3); Telofemura I–IV with 6-6-3-3 setae, Genua I-IV with 5-5- 3-3 setae of them 1-1-0-0 bipectinate, respectively. Tibiae I–IV with 2-2- 2-2 bipectinate setae; claws with accessory process possess 7–10 tines.

Abé (1998) and Pepato & Silveira (2015) provided a tabular key scoring 26 characters for distinguishing species.

Based on the combined tabular keys, the new species R. cilbizi sp. nov. closely resembles R. major Bartsch 2005 from Singapore, Pacific Ocean (Tropical West) by sharing anterior dorsal plates with canaliculi, anterior dorsal plate anteriorly truncated, single pair of setae on PD, AE and PE on either side with 1 adjunct setae, leg chaetotaxy of genua (5-5-3-3) and tibiae (5-5-5-5) and numbers of perigenital setae both female (5 vs. 5‒7) and male (9 vs. 9‒12).

However, the new species differs from R. major Bartsch, 2005 by smaller idiosoma (288–330 vs. 500–560) and gnathosoma (87 vs. 157), forms of claw and accessory process (claws with accessory process and possess 8–10 teeth in new species, while accessory process is lacking and claws smooth in R. major ), different leg chaetotaxy of telofemura, the number of bipectinate setae on genua II (1 vs. 0) and tibia II, III (2-2 vs. 1-1), shorter carpite on the legs (in the new species, carpite of tarsi I and II 13‒15 long, of tarsi III and IV 15‒20 long vs. carpites I and II 22 long, of carpites III and IV 29).