Dytiscacaridae HAJIQANBAR AND LINDQUIST 2018, FAM. NOV.
Creators: name: Mortazavi, Abdolazim
name: Hajiqanbar, Hamidreza
name: Lindquist, Evert E.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Dytiscacaridae

description: DYTISCACARIDAE HAJIQANBAR AND LINDQUIST FAM. NOV.
Type genus
Dytiscacarus Hajiqanbar and Lindquist gen. nov.
Diagnosis
There are four postembryonic instars (larva, protonymph, deutonymph and adult) characterized by the following combination of characters: gnathosoma without dorsal setae, but with one pair of ventral setae m in rostral area; palps moderately well developed, projecting anteromedially, freely from apices of infracapitulum, with three segments (trochanter, femorogenu and tibiotarsus), lacking a thumb-claw process; trochanter nude, femorogenu with two setae (dFe and dGe), tibiotarsus with four setae (acm, sul, ul’ and ul”), seta ul’ characteristically strongly curved; cheliceral bases reduced, with a remnant covering basal dorsum of infracapitulum, and with sheaths deeply embedded and hardly visible encasing long, slender stylets fully retractable into proterosoma; infracapitulum with pharynx muscular, entire, fusiform; paired intercheliceral stigmata located centrally within gnathosoma, with a pair of tracheal trunks leading to neostigmata opening on dorsal infracapitular surface, and with another pair of tracheal trunks extending posteriorly into anterior region of proterosoma. Idiosoma with a series of fragmented tergites separated by striated soft integument in immature instars, which become largely amalgamated in adults; podocephalic canals present anterolaterally on prosoma, above bases of legs I; prodorsum lacking eyes and trichobothria, and not delineated from opisthosoma by a dorsosejugal furrow; idiosomatic setae short, smooth, without neotrichy; all instars with prodorsal sclerotization integrated to some extent with that of opisthosomatic tergite C, such that prodorsal setae sce are together with tergital setae c1, c2 on same plate(s); four pairs of prodorsal setae (vi, ve, sci and sce); dorsal opisthosomatic setal complement with c1, c2, d, e, f1, f2, h1, h2, h3, ps1, ps2 and ps3; cupules absent. Opisthosomatic venter, with anterior and posterior epimera articulating with bases of legs I– II and III –IV, respectively; legs II and III well separated by soft cuticle; extension of opisthosoma markedly abbreviated behind metapodosoma, such that legs III –IV are located near posterior extremity of body. Adult female genital aperture a longitudinal fissure between bases of legs IV, nearly contiguous posteriorly with caudal anus, without genital papillae and genital setae (g series); anal region with three pairs of setae, including ad1 on anal valves, flanked by ps1 and ps2 on soft integument. Adult male with fully formed terminal genital capsule, bearing tiny setae h1, h2, h3 and ps1 on external surfaces; aedeagus well sclerotized, flanked by a pair of accessory processes, with divided birefringent setigenous apices (ps2 and ps3). All instars with all legs each having five segments, similar to one another in size, structure and form of setae, except adult female with legs IV longer than other legs; tarsi I–IV lacking empodium elements, and with paired claws deeply rooted in tarsi and symmetrically modified into well-sclerotized tenent structures; tarsi I and II each with one solenidion; solenidia absent on other leg segments, and eupathidium k absent on tibia I; leg setation reduced from complement present among free-living raphignathines (see genus description).
description: Published as part of Mortazavi, Abdolazim, Hajiqanbar, Hamidreza & Lindquist, Evert E., 2018, A new family of mites (Acari: Prostigmata: Raphignathina), highly specialized subelytral parasites of dytiscid water beetles (Coleoptera: Dytiscidae: Dytiscinae), pp. 695-749 in Zoological Journal of the Linnean Society 184 on page 700