Canacidae Jones

Mathis, Wayne N. & Marinoni, Luciane, 2012, A conspectus on the Canacidae (Diptera) of Brazil, ZooKeys 162, pp. 59-92 : 61-62

Family Canacidae Jones

Canacenae Jones 1906: 170, 198 [as a subfamily of Ephydridae , incorrect formation of the family-group name]. Type genus: Canace Haliday 1837.

Canaceidae . Hendel 1916: 297 [incorrect formation of the family-group name]. Wirth 1951: 245-275 [revision]; 1975: 1-5 [Neotropical catalog]; 1987: 1079-1083 [North American manual].

Canacidae . Enderlein 1935: 235. Mathis 1982: 1-29 [classification]. Buck 2006: 391-392 [familial status]. Munari and Mathis 2010: 1-84 [world catalog].

Tethinidae Hendel 1916: 297; 1917: 45. Type genus: Tethina Haliday. Foster 1976b: 1-4 [Neotropical catalog]. Mathis and Munari 1996: 1-27 [world catalog]. McAlpine 2007: 42 [synonymy].

Diagnosis.

The family Canacidae , sensu lato, is distinguished from other families of the Carnoidea by the following combination of characters: Exclusively or tending to occur in saline habitats (secondarily in freshwater habitats). Minute to moderately small flies, length 0.91-5.0 mm. Head: Postocellar setae developed (absent or reduced in some Canacinae ); dorsal fronto-orbital seta lateroclinate; oral vibrissae weakly differentiated, except for Dasyrhicnoessa Hendel species. Arista dorsal. Face sometimes characterized by 2 shiny protuberances laterad to the facial cavity, just above vibrissal pore ( Tethina , Pseudorhicnoessa ) or nearby ( Afrotethina , Horaismoptera ); face strongly depressed and short ( Dasyrhicnoessa , Horaismopterinae ) or with medial carina ( Tethina ) or even distinctly convex ( Canacinae ). Gena bare, except for ventral or nearly ventral row of setae (peristomal setae), or even with a few anaclinate, strong setae ( Canacinae ). Buccal parts generally strongly sclerotized in Canacinae . Thorax: Precoxal bridge developed. Prescutellar acrostichal setae developed; presutural dorsocentral setae differentiated; anepisternum with 2-3 developed posterior setae, bearing enlarged, dorsally curved seta at posterodorsal corner; usually 1 katepisternal seta present; proepisternal seta developed. Wing generally hyaline, bearing fine, dense microtrichia; subcosta weakened apically, close to vein R1; vein A1 short (except in the sub-Antarctic genus Apetaenus ); vein A2 long, present as a fold. Abdomen: Pregenital sclerites of male short and fused; male tergite 6 fused with sternite 8, forming a usually symmetrical (except in some species of Tethina ), pregenital sclerite; male sternite 7 lost; postgonites firmly connected laterally to base of phallapodeme, distinctly anterior to basiphallus; hypandrium forming a sheath or phallic mantle around the postgonite and basiphallus; epandrium bearing 1-2 pairs of surstyli ventrally, sometimes anterior surstylus lacking ( Canacinae , Tethina ); posterior surstylus partially articulated or fused with epandrium; inner basal corner of surstylus connected to broad interparameral sclerite; cercus very short to exceptionally developed ( Horaismopterinae ); postabdomen of female more or less telescopically retractile; 2 sclerotized spermathecae variable in shape, below with a narrower cylindrical extension into the spermathecal duct; cercus subcylindrical to compressed, or even tapered distally, sometimes bearing stout to pointed, spinelike setulae.

Discussion.

Our concept of Canacidae includes what had been considered as two families, the Canacidae and Tethinidae . At the familial level, J. F. McAlpine (1989: 1472) identified five synapomorphies that link Canacidae with Tethinidae and noted that "...these are clear indications of a sister-group relationship between them ... and may even indicate that they are subgroups of a single family." Other authors ( Hennig 1958; Griffiths 1972; McAlpine 1982; Freidberg 1995) have also suggested a relationship with the family Tethinidae , and Griffiths (1972) further noted some affinities with the Chloropidae and Milichiidae . According to J. F. McAlpine’s (1989) cladogram, which included an analysis of 25 characters for the families Canacidae and Tethinidae , the superfamily Carnoidea (= Chloropoidea ) comprises the families with the following relationships in parenthetic notation: (( Australimyzidae , Braulidae ) Carnidae )(( Tethinidae , Canacidae )(( Milichiidae , Risidae ) (( Cryptochetidae , Chloropidae )))).

More recently, Buck (2006) and D. K. McAlpine (2007) provided rather compelling character evidence, substantiating that these two families are closely associated, and more specifically that the Canacidae sensu stricto are an included lineage within the Tethinidae . Thus, not to include the Canacidae within the Tethinidae would render the Tethinidae as a paraphyletic family. Buck and D. K. McAlpine cited ten synapomorphies that corroborate the monophyly of the family Canacidae sensu lato (the family-group name Canacidae is older than Tethinidae ). These synapomorphies are (only derived state cited): (1) Precoxal bridge present; (2) anepisternum with enlarged, dorsally curved setae at posteroventral corner; (3) vein A2 long, present as a fold; (4) male sternite 6 reduced and divided medially; (5) male tergite 6 fused with sternite 8, forming a symmetrical pregenital sclerite; (6) male sternite 7 lost; (7) postgonites firmly connected laterally to base of phallapodeme, distinctly anterior to basiphallus; (8) hypandrium forming a sheath or phallic mantle around the postgonite and basiphallus; (9) cuticle of larva with covering of fine spicules, and (10) halobiontic in habitat preference, secondarily in freshwater habitats. Buck (2006) further suggested that the sister group to Canacinae sensu stricto is the subfamily Apetaeninae and not Zaleinae and provided four characters as corroborative evidence for this relationship: (1) antennae broadly separated, inserted more or less on protuberant facial tubercles; (2) clypeus distinctly enlarged and produced anteriorly; (3) prementum distinctly emarginated apically; and (4) tentorial arms of head capsule enormously developed and strongly sclerotized.

Key to Subfamilies of Canacidae sensu lato from Brazil