Amphipoda of the Northeast Pacific (Equator to Aleutians, intertidal to abyss): XVIII. Pardaliscoidea - a revised review Donald B. Cadien, LACSD 22 July 2004 (revised 9Dec2014) Preface The purpose of this review is to bring together information on all of the species reported to occur in the NEP fauna. It is not a straight path to the identification of your unknown animal. It is a resource guide to assist you in making the required identification in full knowledge of what the possibilities are. Never forget that there are other, as yet unreported species from the coverage area; some described, some new to science. The natural world is wonderfully diverse, and we have just scratched its surface! Introduction to the Pardaliscoidea The superfamily Pardaliscoidea is represented by three families in the Northeast Pacific, Pardaliscidae, Stilipedidae, and Vitjazianidae, with the bulk of both genera and species in the first. It is among the natant groups of Bousfield and Shih (1994), along with the lysianassoids, the phoxocephaloids, stegocephaloids, dexaminoids, ampeliscoids, pontoporeoids, eusiroids, oediceratoids, melphidippoids, and the synopioids. They also include the hyperiids here. All these groups share some common morphological elements, as they have adopted some common approaches to life. All are callynophorate, at least in the males, and most bear calceoli, although these are lacking in the pardaliscoids, stegocephaloids, dexaminoids, synopioids, and ampeliscoids. Berge et al (2000) placed pardaliscids in their clade 10, which also contained Hyperiopsidae, Vitjazianidae, Hyperiidae, Nihotungidae, Didymocheliidae and Lafystiidae. In their analysis the stilipedids were more closely related to the iphimedioids than to the pardaliscoids. All such analyses are preliminary, and both the composition of the superfamilies and their interrelationships remain largely speculative. The three families composing the superfamily all occur primarily in the deep sea. Brandt et al (2012) characterized all three as occurring primarily at depths below 2000m, being three of the seven families to be so distributed. Diagnosis of the Pardaliscoidea “Plesiomorphic, weakly rostrate, abdominally processiferous, pelagic marine gammarideans with dimorphic terminal male stage; conjoint flagellar segment of antenna 1 and peduncle of antenna 2 bearing brush setae; accessory flagellum usually strong, occasionally vestigial or lacking; eyes (when present) deep reniform, lateral; mouthparts modified; upper lip with distal notch, lobes asymmetrical; lower lip broad, inner lobes well developed or fused; mandibular molar vestigial or lacking, incisor (and lacinia) strong, palp slender, terminal segment often short; inner plates of maxillae sparsely setose, outer plate of maxilla 1 with 7-8 apical spine teeth, palp often greatly enlarged; maxilliped inner plate reduced, outer plate large, palp strong; coxal plates shallow, 4th not strongly excavate behind; coxae 5-7 equi- or anteriorly lobate; gnathopods 1 and 2 non-amplexing, subsimilar, subchelate or simple, occasionally enlarged and raptorial; peraeopods 3 and 4 tend to be raptorial; peraeopods 5-7 elongate, homopodous or heteropodous, bases not broadly expanded; brood plates broad; coxal gill on peraeopod 7; pleopods powerful; uropods lanceolate, tips weakly 1 spinose, rami unequal; uropod 3 lanceolate, foliaceous, outer ramus 2-segmented; telson lobes deeply separated (apices with notch and spines).”(from Bousfield 1978). Ecological Commentary The pardaliscoids are mostly deep-sea creatures, found from the bathyal into the abyssal and/or hadal zones. Some species occur at shelf depths, but these are the exception. In the deep sea some members of the Pardaliscidae have been observed to be attracted to baited traps, and are in consequence part of the scavenging guild. While most of the deep-sea scavengers are lysianassoids, the pardaliscoids also share this feeding mode. Jamieson et al (2011 present observational evidence that members of the pardaliscid genus Princaxelia are bait-attracted scavengers in trenches. This nutritional mode does not seem to be active at slope and shelf depths for pardaliscoids. In an extensive review of the scavenger guild in Australian waters at those depths, Lowry and Smith (2003) reported no pardaliscoids in any of the hundreds of deployed baited traps. Princaxelia (arrow) circling bait at 7703m in the Japan trench (from Jamieson et al 2012) Many pardaliscoids swim actively, and some are true bathypelagic forms (Birstein & Vinogradov 1958, 1960, 1964, 1970; Thurston 1976). Sainte –Marie and Brunel (1985), in their investigation of swimming amphipods from shelf depths in the NW Atlantic, reported Pardalisca cuspidata as being taken in the suprabenthos. Since most pardaliscoids are not found at shelf depths this quantitative investigation underestimated swimming in the group. Perhaps because of their swimming habit some pardaliscoids have extraordinarily broad distributions, being reliably reported from wide spread points on the globe (see for instance Hendrycks and Conlan 2003). Such swimming is typical of non-mate guarding species that do not engage in prolonged precopula (Conlan 1991). It also places pardaliscoids in the “natant” group of families of Bousfield and Shih (1994). The superfamily lacks calceoli, but bears a well developed sensory callynophore (Lowry 1986). This structure may be present in both sexes, or absent in females, depending on genus. If present in both sexes it is generally better developed in the male, arguing for 2 involvement in mate search as well as prey location. Other sexual differences are variable, with males and females almost identical in some pardaliscoids, while differing substantially in others. Where differences are marked, they usually involve differences in ornamentation of the pleosome or urosome. The two described species in the pardaliscid genus Parpano, for instance are believed to perhaps be male (with urosomal teeth) and female (lacking them) of a single species (J. L. Barnard 1964). In other genera such ornamentation is constant between the sexes. Key to NEP Pardaliscoid genera Biswas et al (2009) have provided a key to all the genera of the Pardaliscidae. I will provide only a key to the families in the NEP. There are two regional genera in the Stilipedidae, which will also be keyed. 1. Coxa 4 posteriorly excavate……………………………………..Stilipedidae..2 Coxa 4 not excavate, anterior and posterior margins subparallel…………..…3 2. P7 longer than P6 or P5, dactyl as wide as propod……………………..Stilipes P7 subequal to P5 and P6, dactyl more slender than propod…………….Astyra 3. Mandibular molar large, triturative……………..……....Vitjazianidae Vemana Mandibular molar absent…………………………………..……..Pardaliscidae NEP Pardaliscoidea from McLaughlin et al. (2005) augmented by known provisionals *= Taxon on SCAMIT Ed. 9 list (Cadien and Lovell 2014). Valid taxa bolded, synonyms not. [Listed provisional species are from thesis (Dickinson 1976), or consulting taxonomic investigations (Thomas in Blake et al 1992; Cadien in Lissner et al 1986) within the area. In nearly all cases they are not documented by voucher descriptions or available specimens. They are presented here to provide some idea of the potential undescribed diversity of the group within the NEP] Family Pardaliscidae Pardaliscidae sp G Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2820m Antronicippe serrata Stock and Iliffe 1990 – Galapagos Ids, Ecuador: 24m Caleidoscopsis copal (J. L. Barnard 1967) – Cascadia Abyssal Plain, Oregon to Baja Abyssal Plain, Mexico: 2398-2816m Caleidoscopsis tikal (J. L. Barnard 1967) – Cascadia Abyssal Plain, Oregon to off Northern Baja California, Mexico: 1720-2824m Caleidoscopsis sp A (Dickinson 1976§) – Cascadia Abyssal Plain, Oregon: 2787- 2820m Caleidoscopsis sp B (Dickinson 1976§) – Cascadia Abyssal Plain, Oregon: 2800- 2820m Halice aculeata Chevreux 1912 – Northeast Atlantic, Indian Ocean, Southwest Pacific, NEP off Central California: 0-10,500m [4000m in NEP] Halice cocalito J. L. Barnard 1964 – Gulf of Panama: 1749m Halice hesmonectes Martin, France and Van Dover 1993 – East Pacific Rise, off southern Mexico; 2520m Halice ulcisor J. L. Barnard 1971 – Oregon: 600-800m 3 Halice sp A Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2787-2816m Halice sp B Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2816m Halice sp W Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2820m Halice sp X Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2820m Halice sp Y Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2815m Halice sp Z Dickinson 1976§ - Cascadia Abyssal Plain, Oregon: 2813-2824m Halicella halona J. L. Barnard 1971 (see Rhynohalicella halona) Halicoides lolo (J. L. Barnard 1971) – Oregon: 800m Halicoides synopiae (J. L. Barnard 1962) – Monterey, Central California to outer coast of Baja California, Mexico: 52-1720m Halicoides sp 1 (Thomas 1992§) – Gulf of the Farallones: 2045-3085 Macroarthrus victoriae Hendrycks and Conlan 2003 – Central California: 4050m Nicippe tumida Bruzelius 1859 – Northeast Atlantic to North Pacific circumboreal, to Bahia San Cristobal, Mexico: 34-1367m Octomana hadromischa Hendrycks and Conlan 2003 – Central California: 1787-4050m Pardalisca endeavouri Shaw 1989 – Explorer Ridge west of Vancouver Id., Canada: 1797m Pardalisca marionis Stebbing 1888 – Gulf of the Farallones: 2045-3085m Pardalisca tenuipes Sars, 1893 – North Atlantic, North Pacific to SCB: 32- 1094m Pardalisca sp J. L. Barnard 1967 – Santa Maria Basin, Central California