Iulopis mirabilis Bovallius, 1887

Zeidler, Wolfgang, 2004, A review of the families and genera of the hyperiidean amphipod superfamily Phronimoidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 567, pp. 1-66 : 42-46

Iulopis mirabilis Bovallius ( Figs 4–6 )

Iulopis mirabilis Bovallius, 1887: 18 . — Shoemaker 1945: 238–242, figs 36 & 37. Bowman & Gruner 1973: 33, fig. 41 (part). Brusca 1981: 20 (key), 42. Vinogradov et al. 1982: 280–282, fig. 141. Vinogradov 1990: 61. Vinogradov 1991: 261 (table).

Euiulopis mirabilis – Bovallius 1889: 125–128, pl. 8, figs 19–33.

Type material

Type material of I. mirabilis is in the SMNH (No. 1750). The type locality is the “Pacific, Bay of Panama ” according to Bovallius (1887). Bovallius (1889) provides more detailed information: “in the Bay of Panama; taken in 1882 by the author among the Isles de las Perlas, at San Jose, and in the Bahia de Tychs, Isla del Reg.”

Material examined (63 specimens)

Types. Syntypic material from “ Panama Bay 1882”: male in spirit with G1 & 2 and P3 missing from the left; one microscope slide with mouthparts, antennae and G1 .

Other material examined. North Atlantic: 2 lots ( USNM), 10 lots ( ZMUC), 19 specimens. South Atlantic : 1 lot ( ZMUC), 1 specimen. North Pacific : 6 lots ( ZMUC), 13 specimens. South Pacific : 2 lots ( ZMUC), 2 specimens. North Indian : 4 lots ( ZMUC), 7 specimens. South Indian: 14 lots ( ZMUC), 16 specimens. Central Indo­Pacific: 1 lot ( ZMB) , 1 lot ( ZMUC), 4 specimens .

Diagnosis

Body; length of sexually mature specimens 6–8 mm; less hirsute than I. loveni , only sparsely hirsute on dorsal part of head. Antennae 2 of female three­articulate. Mandibular palp present only in male. Gnathopod 1 subchelate, carpal process rounded, not produced, with scattered robust setae in addition to short, slender setae. Gnathopod 2 with triangular carpal process, produced to about middle of propodus, with scattered robust setae in addition to short, slender setae. Uropod 1–3 of female with rami about 0.75x length of respective peduncles, with relatively long terminal setae on exopod of U1 & 2 and on both rami of U3. Telson of female about 0.7x length of peduncle of U3.

Remarks

This is an extremely rare species, and prior to this study was known from less than ten specimens worldwide. It is readily distinguished from its only congener, I. loveni , by the gnathopods, and in addition, males are distinguished by the presence of a mandibular palp and females by the presence of three­articulate second antennae. Specimens with pereopods 5–7 approaching the prehensile condition, found in some specimens of I. loveni , are not known. There are no records of this species in association with gelatinous plankton.

Distribution

Prior to this study, this species was only known from the North Atlantic Ocean ( Bermuda) and from the tropical Pacific Ocean (off California, Bay of Panama, approx. 20ºS, 81ºW). Additional material, mainly from the Dana expedition ( Jespersen & Tåning 1934), now extends the distribution of this species to the tropical and warmer waters of all the world’s oceans. However, unlike its congener, it is not known from the Mediterranean.

Figures

FIGURE 4. Iulopis mirabilis. A, lateral view of female, 5.3 mm, tropical NE Atlantic (Dana stn. 4001iii). B, lateral view of male, 5.2 mm, SW Indian Ocean (Dana stn. 3935ii). Scale bars = 0.5 mm (A, B), 0.2 mm (remainder).

FIGURE 5. Iulopis mirabilis, female, 5.3 mm, tropical NE Atlantic (Dana stn. 4001iii), (fine setae only illustrated along margins). Scale bar = 0.2 mm.

FIGURE 6. Iulopis mirabilis, male, 5.2 mm, SW Indian Ocean (Dana stn. 3935ii). Scale bar = 0.1 mm.