Cebocaridae, Lowry & Stoddart, 2011

Lowry, J. K. & Stoddart, H. E., 2011, The new deep-sea families Cebocaridae fam. nov., Cyclocaridae fam. nov. and Thoriellidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea), Zootaxa 2747 (1), pp. 53-68 : 55-56

Cebocaridae fam. nov.

( Figs 1 , 2 )

Diagnostic description. Head exposed or partially covered by pereonite 1 and coxa 1; much deeper than long, extending well below insertion of antenna 2, without cheek notch. Antennae calceoli present or absent in male. Antenna 2 peduncular article 3 without distal hook. Epistome with proximal portion not produced. Mouthpart bundle subquadrate. Mandible incisors well developed, asymmetrical, left straight, minutely serrate, right convex, smooth; left lacinia mobilis present or absent, if present then blade-like, broader than long, with serrate margin or rod-like; accessory setal row with 5 or less robust setae, without distal setal tuft; molar vestigial or absent; palp present or absent, if present then inserted approximately midanteriorly. Maxilla 1 inner plate with pappose setae along medial margin or with apical pappose setae; outer plate with setal-teeth in modified 8/3 crown arrangement, setal-teeth large; palp large, with apical robust setae. Maxilla 2 inner plate significantly shorter than outer plate, inner plate with or without oblique row of facial setae (weak when present). Maxilliped outer plate present, medial setae vestigial or absent, with apical slender setae; palp 4-articulate, article 4 well developed.

Gnathopod 1 simple; coxa vestigial; ischium short or long; carpus short; propodus small; dactylus slightly curved. Gnathopod 2 coxa vestigial. Pereopods some prehensile; distal spurs absent. Pereopod 4 coxa with posteroventral lobe well developed, weak or absent. Pereopod 5 coxa anterior and posterior lobes subequal, or posterior lobe deeper than anterior lobe.

Uropod 3 rami biramous. Telson cleft or entire.

Type genus. Cebocaris J.L. Barnard, 1964 .

Included genera. The Cebocaridae includes 9 genera: Cebocaris J.L. Barnard, 1964 ; Crybelocephalus Tattersall, 1906 ; Crybelocyphocaris Shoemaker, 1945 ; Cyphocarioides Birstein & Vinogradov, 1970 ; Mesocyclocaris Birstein & Vinogradov, 1964 ; Mesocyphocaris Birstein & Vinogradov, 1960 ; Metacyclocaris Birstein & Vinogradov, 1955 ; Metacyphocaris Tattersall, 1906 ; Paracyphocaris Chevreux, 1905 .

Remarks. Among lysianassoid amphipods only six family-level taxa have the first and second coxae vestigial: Cebocaridae , Cyclocaridae , Cyphocarididae , Lepidepecreellidae , Thoriellidae and Wandinidae . Among these taxa only the cebocarids and the cyclocarids have the inner plate of maxilla 2 significantly shorter than the outer plate. All cebocarids have some pereopods prehensile while no cyclocarids have prehensile pereopods. Cebocarids are distinguished by their much deeper heads which in cyclocarids are only slightly deeper than long. In addition cebocarids have the mandibular molar vestigial or absent and the maxilla 1 setal-teeth in an 8/3 crown arrangement whereas in cyclocarids the molar is a well developed setose tongue and the maxilla 1 setal-teeth are in a 7/4 crown arrangement, adaptations for scavenging.

There is very little known about the biology of cebocarid amphipods aside from the study of Bowman & Wasmer (1984) which suggested that Paracyphocaris praedator Chevreux, 1905 is an egg-mimic that feeds upon the eggs of the pelagic caridean shrimp Oplophorus novaezeelandiae de Man, 1931 . Based on slim evidence presented by K.H. Barnard (1932) and Shoemaker (1945) Bowman & Wasmer (1984: 847) suggested that all cebocarid genera might be ‘associated with the marsupia of deep-sea pelagic shrimps’.

Generic distinctions between some of the cebocarid genera are very slight. A complete revision of the family is needed, at both generic and species level (see remarks under Metacyphocaris helgae Tattersall, 1906 ).

Figures

FIGURE 1. Morphological features of the Cebocaridae fam. nov. Habitus—Crybelocyphocaris tattersalli Shoemaker, 1945. A2, UR—Metacyphocaris helgae Tattersall, 1906.*A2, LMD, RMD—Metacyclocaris polycheles Birstein & Vinogradov, 1955. *LMD, *RMD—Mesocyphocaris longicaudatus Birstein & Vinogradov, 1960. MD, MX2—Cyphocarioides elongatus Birstein & Vinogradov, 1970. MX1—Crybelocephalus megalurus Tattersall, 1906.

FIGURE 2. Morphological features of the Cebocaridae fam. nov. G1, G2, **P7, **T—Crybelocephalus megalurus. P7— Cyphocarioides elongatus. *P7—Mesocyclocaris gracilis Birstein & Vinogradov, 1964. U3, T—Metacyphocaris helgae. *U3, *T—Metacyclocaris polycheles.