Eucalliacidae Manning and Felder, 1991

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 122-125

Eucalliacidae Manning and Felder, 1991

Figures 18 , 19

Eucalliinae Manning and Felder, 1991: 781 (misspelling).

Eucalliacinae Sakai, 1999a: 108–109 .— Ngoc-Ho, 2003: 487–489 (partim).— Sakai, 2005b: 195–196 (partim).— Sakai,2011: 493–494.— Hyžný, 2012: 51–52.— Sakai, 2017a: 1122.— Sakai, 2018: 734–738.

Eucalliacidae .— Sakai, 2011: 491.— Sakai and Türkay, 2014: 190 (outdated key to genera).— Sakai, 2017a: 1122.—Dworschak, 2018: 17.— Sakai, 2018: 734–738.

Diagnosis. Rostrum flat, short, triangular, shorter than eyestalks; median carina absent; gastric carinae absent; cervical groove well defined; suture between ocular lobe and end of linea thalassinica horizontal in lateral view; anterior branchiostegal margin sinusoidal or semicircular; anterior branchiostegal lobe simple, scarcely calcified, merging smoothly with anterodorsal branchiostegal angle and anterolateral margin of carapace; posterior margin of carapace without lateral lobes. Pleomere 1 without anterolateral lobes, weakly chitinised. Eyestalks flattened, contiguous, with subdistal dorsal cornea. Antennal scaphocerite rudimentary. Maxilla scaphognathite without long seta on posterior lobe extending into branchial chamber. Maxilliped 1 epipod with acute anterior lobe lying alongside exopod. Maxilliped 3 propodus about as wide as long; dactylus dilating, truncate, with dense field of setae on distal margin. Cheliped merus lower margin smooth; major cheliped with distinctively flattened palm, sometimes with strong crest above and below. Pereopod 3 propodus broad, with proximal lobe on lower margin, without distal spiniform setae on lateral face (often with 1 distal spiniform seta on lower margin). Pereopod 5 minutely chelate or subchelate. Female pleopod 2 rami narrower, with more reduced setation than pleopods 3–5; endopod flattened and 2–5 times as long as wide. Pleopods 3–5 with oblique peduncles meeting mesially, endopods triangular, with straight mesial margin, exopods attached laterally, proximally lobed, longer than and enclosing endopods; appendices internae reduced and almost embedded in mesial margin of endopod. Uropodal exopod with elevated dorsal plate.

Remarks. Eucalliacidae differ from Callianopsidae , the only other family with a dense field of setae on the distal margin of a truncate maxilliped 3 dactylus, in the propodus of maxilliped 3 being wider than long (rectangular in callianopsids), lacking a lateral longitudinal ridge on the eyestalk (present in callianopsids) and the uropodal exopod having a dorsal plate (absent in callianopsids).

The family and generic concepts used in redefining Eucalliacidae with the support of molecular data, morphological data or both (Robles et al., in press), differ markedly from those tabulated by previous authors including Sakai and Türkay (2014) and Sakai (2018 and his earlier works). Some characters used by previous authors are too variable or not able to be easily categorised for generic diagnosis: anterolateral projections on the carapace, structure of the male pleopod 1, size of appendices internae on pleopods 3–5, relative length of the uropodal endopod, and concavity or convexity of the telson margin. Several of the characters used in this work to separate genera were not considered by these authors.

The family Eucalliacidae has a complex taxonomic history. Manning and Felder (1991) erected the subfamily for two genera, Eucalliax and Calliax . Ngoc-Ho (2003) erected a new genus Calliaxina and differentiated these three genera from Paraglypturus Türkay and Sakai, 1995 . Sakai (1999a, 2005b) recognised only Calliax and Paraglypturus , synonymising Eucalliax and Calliaxina with Calliax .

Sakai (2011) divided Eucalliacidae into two subfamilies, Eucalliacinae and Calliapaguropinae , the latter for a single genus, Calliapagurops de Saint Laurent, 1973 . Sakai’s remarks on the new subfamily pointed out differences between Calliapagurops and Callichirus (a member of another subfamily) but nothing on why the genus was similar to remaining eucalliacids. It is not at all similar. As stated much earlier by Ngoc-Ho (2003), Calliapagurops is clearly a member of Callichirinae , here treated as Callichiridae , with which it shares many features. As a result, Sakai’s diagnosis of the family comprised only characters true for all or most callianassoids (scaphognathite without long distal seta; pereopod 1 chelate, unequal, dissimilar; uropodal exopod with dorsal plate but without notch) or ambiguous (carapace with or without dorsal oval, maxilliped 3 dactylus “subtriangular” or digitiform). Sakai’s (2011) Eucalliacinae revived the genera he had earlier dismissed and added three to bring the total to seven. He re-diagnosed Calliaxina using one character alone, not one of those proposed by Ngoc-Ho (2003), but his arguments were not supported by recent molecular or morphological analysis (Robles et al., in press). In this same paper, Sakai corrected his earlier statement (2005) that Calliax was the type genus but his reasoning was false. Sakai and Türkay (2014) added an eighth genus and tabulated characters that they believed distinguished them.

Sakai (2018) re-diagnosed Eucalliacinae without emphasising the unifying propodus and dactylus of maxilliped 3. He erected three new genera, Bakercalliax , Heardcalliax and Manningcalliax , here treated as junior synonyms of Eucalliaxiopsis . He argued heavily on separation of the genera based on “organs involved in reproduction”, especially male pleopods, whether pleopod 1 was “simple” or “subchelate”, and on differences in the degree of fusion of the appendices masculina and interna. Pleopod 1 of the male varies considerably and erratically among species of Eucalliacidae and appears to have little generic value, contrary to Sakai’s (2018) view (figs 19g –s).

Eucalliaxiopsis was differentiated from Eucalliax on account of its unusual pleopods 1 and 2. The male pleopod 1 of the type species, Eucalliax cearaensis , bears long setae on article 2 (Rodrigues and Manning, 1992), whereas in the type species of Eucalliax this article is simple. We were unable to confirm the structure of the male pleopod 1 of Eucalliax cearaensis (type mislaid) but Rodrigues and Manning (1992b: fig. 2s) can be variously interpreted. Apart from the long setae, article 2 is similar to that of, for example, C. jonesi and E. panglaoensis (cf. Dworschak, 2006). In most species of Calliaxina and Eucalliaxiopsis , the male pleopod 1 has long distal setae on article 1 and a broad article 2 and a curved apex, sometimes with an intermediate lobe. This is seen in C. novaebritanniae , C. kensleyi , C. punica , C. sakaii , E. jonesi , E. mcilhennyi and E. panglaoensis (figs 19i–n; see also figures in Dworschak, 2006, 2014; Heard, 1989; Felder and Manning, 1994; Manning and Lemaitre, 1994; Ngoc-Ho, 2003; de Saint Laurent and Manning, 1982). In contrast, the illustrated male pleopod 1 of C. bulimba (fig. 19g; Dworschak, 2005: figs 5c, d; Poore and Griffin, 1979: fig. 21g), E. inaequimana (fig. 19o, p; Dworschak, 2014: figs 4j–l) and E. madagassa ( Ngoc-Ho, 2014: fig. 2S, as C. thomassini ) has article 1 with distal long setae and a short oblique article 2. However, a newly discovered male of C. bulimba differs in having a bilobed article 2 with a separate appendix interna (fig. 19h). This would appear to be a precursor of the more typical eucalliacid form (figs 19i–n). A third form of male pleopod 1 is seen in E. aequimana where article 2 is longer than article 1, parallel-sided and setose ( Dworschak, 2014: figs 9h, i). These forms appear to cross generic lines. The role of ontogeny in the morphology of pleopod 1 is poorly understood but it is evident from some studies that the male pleopod 1 does not appear fully formed in juveniles ( Dworschak, 2005, 2006, 2014). Development of the male pleopod 1 with age seems probable.

This throws considerable doubt on the validity of three recently erected genera Bakercalliax Sakai, 2018 , Heardcalliax Sakai, 2018 and Manningcalliax Sakai, 2018 , all differentiated largely on the basis of the male pleopod 1. Sakai (2018) also noted differences between the relative sizes of the appendices interna and masculina of pleopod 2 but this would scarcely seem of generic value. The type species of all three genera have a transverse ridge on the telson and lack an exopod on maxilliped 3. As a consequence, all are synonymised with Eucalliaxiopsis . Sakai (2011) did not compare Eucalliaxiopsis with Calliaxina , which it resembles more closely, especially in the male pleopod 2. Calliaxiopsis Sakai and Türkay, 2014 , was synonymised with Calliaxina by Poore and Dworschak (2017). Sakai’s shuffling of species in his three papers has resulted in some species being listed as members of as many as five genera at different times during their history.

Our morphological analysis(Robles et al., in press) recognised a single clade containing all eleven of the genera included by Sakai (2018) in Eucalliacinae . This monophyly was not supported by the molecular phylogram (Robles et al., in press) where three sequential paraphyletic clades are evident, equivalent to Eucalliaxiopsis + Calliaxina , Calliax and Eucalliax .

Figures

Figure 18. Diagnostic characters for genera of Eucalliacidae.Posterior carapace, sternite 7, pleopod1, coxa 4, basis of pereopod 5: a,Pseudocalliax. Carapace, eyestalks, antennules, antennae: b, Eucalliax. Telson, uropod: c, Calliaxina; d, Eucalliaxiopsis. Pleomere 6, telson, uropod: e, Paraglypturus; f, Eucalliax. Major cheliped: g, Paraglypturus; h, Eucalliax. Minor cheliped: i, Paraglypturus; j, Calliax; k, Pseudocalliax. Pereopod 3: k, Calliaxina; l, Calliax. Pereopod 4: m, Paraglypturus. Original illustrations: a, Pseudocalliax tooradin NMV J303; e, Calliaxina SA-01, UF 36699; h, Eucalliax quadracuta, Panama, NHMW 25916.

Figure 19.Diagnostic characters for genera of Eucalliacidae. Maxilliped 3: a, Calliaxina punica; b, C. SA-01;c,Andamancalliax; d,Eucalliaxiopsis; e, Pseudocalliax; f, Calliax. Male pleopod 1: g, h, Calliaxina bulimba; i, C. kensleyi; j, C. SA-01; k, C. punica; l, C. sakaii; m, Eucalliaxiopsis panglaoensis; n, E. mcilhennyi; o, p, E. inaequimana; q, Calliax; r, Pseudocalliax; s, Paraglypturus. Male pleopod 2: t, Calliaxina; u, v, Paraglypturus; w,Eucalliax; x,Eucalliaxiopsis. Female pleopod 2, y,Paraglypturus: z,Calliax; z’, Calliaxina. Female pleopod 3: z’’,Paraglypturus. Original illustrations: b, i, Calliaxina SA-01, UF 36699; g, C. bulimba, MNHN-IU-2013-7097; h, C. bulimba, NMV J71686; w, Eucalliax quadracuta, NHMW 25916; o, Eucalliaxiopsis inaequimana, MNHN-IU-2013-10008; p, E. inaequimana, UF 16512; e, r, Pseudocalliax tooradin NMV J303; u, v, Paraglypturus calderus, MNHN Th1416.