Regaliidae

Lowry, J. K., 2006, New families and subfamilies of amphipod crustaceans, Zootaxa 1254, pp. 1-28 : 18-21

Regaliidae fam. nov.

( Fig. 5 )

Type genus

Regalia K.H. Barnard, 1930 .

Description

Head. Exposed; as long as deep; lateral cephalic lobe rounded or absent, rounded apically; anteroventral margin concave or rounded, anteroventral margin not recessed, anteroventral margin shallowly excavate or not excavate; anteroventral corner rounded, or subquadrate; rostrum moderate length; eyes present, well developed, ovoid. Body subcylindrical; body without setae; smooth. Antenn a 1 subequal in length to antenna 2; peduncle with sparse slender setae; peduncular article 1 longer than article 2; longer than article 3; shorter than article 1; peduncular article 3 short (half or less length of article 2); peduncular articles 1–2 not geniculate; peduncular articles 2–3 not geniculate; accessory flagellum absent; primary flagellum 5­ or more articulate; callynophore present or absent. Calceoli absent. Antenna 2 medium length; peduncle with many brush setae; without hook­like process; flagellum longer than peduncle; 5­ or more articulate; normal. Mouthparts well developed. Mandible incisor minutely dentate, straight; lacinia mobilis present on both sides; accessory setal row without distal tuft; molar small, nontriturative or with tiny triturating patch, non­triturative; palp 3­articulate. Labium outer lobes smooth. Maxilla 1 present; inner plate setose apically; palp large, 2­articulate, not clavate. Maxilla 2 inner plate present; outer plate present, with oblique setal row; maxilla 2 with weakly setose medial margin. Maxilliped inner and outer plates well developed; palps well developed; outer plate longer than palp article 1, not longer than palp article 2, apical robust setae present; palp 4­articulate.

Pereon. Pereonites complete. Coxae 1–7 reduced. Coxae 1–4 as long as broad or broader than long, overlapping, coxae not ventrally acute. Coxae 1–3 similar in size. Coxae 2–4 none extensively broadened. Gnathopod 1 similar in males and females (not sexually dimorphic); similar in size to gnathopod 2; similar in form to gnathopod 2; simple or weakly subchelate; coxa subequal to coxa 2; anteroventral corner produced, acute or subacute; merus and carpus not rotated; carpus/propodus not cantilevered; carpus subequal to propodus, not produced along posterior margin of propodus; without robust setae along palmar margin; dactylus large. Gnathopod 2 similar in males and females (not sexually dimorphic); simple, or subchelate; coxa subequal to but not hidden by coxa 3; ischium short; merus not fused along, or produced away from, posterior margin of carpus; carpus short, subequal or longer in length to propodus, not produced along posterior margin of propodus; dactylus well developed. Pereopods none prehensile. Pereopods 3–4 not glandular. Pereopod 3 coxa well developed; carpus shorter than propodus, not produced; dactylus well developed. Pereopod 4 coxa subequal to coxa 3, not ventrally acute, without posteroventral lobe; carpus shorter than propodus, not produced; dactylus well developed. Pereopods 5–7 with few robust or slender setae. Pereopod 5 coxa larger than coxa 4, equilobate; basis expanded, subrectangular, without posteroventral lobe; dactylus well developed. Pereopod 6 basis expanded. Pereopod 7 similar in structure to pereopod 6; basis expanded, subovate, without dense slender setae.

Pleon. Pleonites 1–3 without transverse dorsal serrations, with lateral teeth, pleonites 1–3 each with dorsal carina or carinae; without slender or robust dorsal setae. Epimeron 1 well developed. Epimeron 2 without setae. Urosome not dorsoventrally flattened; urosomites 1–3 free. Urosomite 1 carinate or urosomites not carinate; longer than urosomite 2. Uropods 1–2 apices of rami with robust setae. Uropods 1–3 similar in structure and size. Uropod 1 peduncle without long plumose setae, without basofacial robust setae, without ventromedial spine. Uropod 2 without dorsal flange, without ventromedial spine. Uropod 3 peduncle short, without medial process; biramous; rami lanceolate; outer ramus longer than peduncle, without recurved spines; inner ramus longer than outer ramus, inner ramus not apically setose. Telson laminar, as long as, or broader than long, emarginate, dorsal or lateral robust setae absent, apical robust setae absent.

Generic composition

Regalia K.H. Barnard, 1930 .

Remarks

Regalia is not a well known genus, but it has always been considered as a calliopiid (sensu stricto) or eusirid (sensu lato) amphipod. Three workers, K.H. Barnard (1930), Pirlot (1936), Ledoyer (1982) as an unknown genus, and Vinogradov (2004) have all illustrated species in the genus. By putting their illustrations together a picture of the genus emerges. The illustrations of Vinogradov (2004) are the most complete, but they lack a whole animal, antennae of the female, pereopods 5 to 7 and the pleosome/urosome. Pirlot’s (1936) illustration of a whole animal gives us an excellent idea of what these animals look like.

Regalia cannot be a calliopiid because it has a callynophore on antenna 1, brush setae on antenna 2 and a straight, minutely dentate incisor on the mandible. Regalia appears to be most similar to the Pardaliscidae . It differs from members of this family by the absence of an accessory flagellum, the presence of a lacinia mobilis on both mandibles, the presence of a well developed molar, the inner ramus of uropod 3 longer than the outer ramus and the presence of lateral carinae on the pleosome.

Distribution

Indo­West Pacific.

Figures

FIGURE 5. Regaliidae fam. nov. (whole animal, Regalia gracilimana, after Pirlot 1934; remainder, Regalia oculata, after Vinogradov 2004).