Inermiphonte, Huys & Lee, 2009

Huys, Rony & Lee, Wonchoel, 2009, Proposal of Marbefia, gen. n. and Inermiphonte, gen. n., including updated keys to the species of Pseudonychocamptus Lang, 1944 and Paralaophonte Lang, 1948 (Copepoda, Harpacticoida, Laophontidae), ZooKeys 23 (23), pp. 1-38 : 18-21

Proposal of Inermiphonte , gen. n.

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The taxonomic position of Laophonte danversae Hamond, 1969 has been surrounded by controversy since its original description. Hamond (1969) suggested a close rela-

a Chislenko’s [1967 – reproduced in Kornev and Chertoprud (2008)] female from the White Sea shows a P5 exopod ♀ with length/width ratio 1.64 and a P1 endopod which is distinctly more slender than in Sars’ (1908a) material; this record is considered doubtful and may well refer to another as yet undescribed species.

tionship with L. cesareae Por, 1964 (currently placed in Loureirophonte ; cf. Fiers 1993 – see below) without giving any compelling evidence for this affiliation. Although his description of L. danversae was based solely on females from West Runton the author also illustrated a single male from the same locality under the nondescript name “Laophontid male,?gen.,?sp.”. Hamond (1969) suggested that the latter might have been the unknown male of L. danversae , were it not for the marked differences observed in the rostrum, caudal rami and the armature on the P2–P4 exopods. In an addendum to his paper he also remarked that “Laophontid male,?gen.,?sp.” and the male of Laophonte ? drachi Médioni & Soyer, 1966 shared the same type of sexual dimorphism on the P3 endopod and that the latter species was obviously closely related to L. danversae . As pointed out by Hicks (1982), Bodin (1971) clearly misinterpreted Hamond’s remarks when he suggested conspecificity between L. danversae and L.? drachi . This misconception was perpetuated in the literature by Wells (1976) who considered Hamond’s “Laophontid male,?gen.,?sp.” the true male of L. danversae and subsequently by Bodin (1979) who regarded both female and male L. danversae as junior synonyms of L.? drachi . The issue of the unknown male of L. danversae was finally resolved by Hicks (1982) who provided its first description based on material from Robin Hood’s Bay ( England). Hicks demonstrated that Hamond’s (1969) “Laophontid male,?gen.,?sp.” and the males of L. danversae and L.? drachi were significantly different in the swimming legs, leg 5 and caudal rami, corroborating their distinct specific identity but his comparative analysis did not, however, contribute anything new to elucidating the relationships of this species group within the Laophontidae . Hamond (1969) had previously suggested that L. danversae might best be classified as an “anomalous species” of Laophonte , which does not fit into any of the species groups proposed by Lang (1948). Médioni and Soyer (1966) tentatively assigned L.? drachi to the inopinata -group of Laophonte and noted some similarities with L.? platychelipusoides Noodt, 1958 (currently placed in Coullia Hamond, 1973 ; cf. Hamond 1973; Huys 2009a). Lee and Huys (1999) instead recognized a relationship between L. danversae and the laophontid genera that display a similar type of setal sexual dimorphism on the endopods of P3–P4 (Table 1) but neither formally included the species in the PWPH -clade or removed it from its floating status in the genus Laophonte . Laophonte danversae is here fixed as the type species of a new genus Inermiphonte , gen. n. which also includes Hamond’s (1969) “Laophontid male,?gen.,?sp.”. Inermiphonte is provisionally regarded as the sistergroup of Harrietella based on the following synapomorphies: (1) P2–P4 exp- 3 ♀ /♁ without inner setae, (2) P4 exp-2 without inner seta (exp-2 not expressed in Harrietella but inner margin of distal exopod segment without inner setae), (3) P3 enp- 1 ♀ without inner seta, (4) P3 enp- 2 ♀ with 0–1 seta, and (5) P4 enp- 2 ♀ without inner setae.

Diagnosis. Laophontidae . Body linear or dorsoventrally depressed. Posterior margins of abdominal somites usually with spinule rows dorsally and ventrally. Rostrum delimited at base; broadly triangular, prominent. Genital double-somite ♀ with lateral incisions and ventrolateral internal chitinous ribs marking original segmentation. Pleural extensions of ♀ abdominal somites moderately developed. Caudal ramus rectangular or conical, longer than wide; inner margin with spinules; with 7 setae; setae IV and V well developed, pinnate; seta VI reduced, setiform. Anal operculum finely spinulose or smooth.

Sexual dimorphism in antennule, P3 (and occasionally P4) endopods, P5, P6 and in genital segmentation.

Antennule relatively short and 6- or 7-segmented in ♀; 6- or 7-segmented and (sub)chirocer with 1–2 segments distal to geniculation in ♁; segments with spinular ornamentation along anterior margin of segments 1–4 in ♀ and 1–3 in ♁; segments 1–2 without processes; dorsal surface of segment 1 with 2 thick pinnate spines; with aesthetasc on segment 4 (♀) or 5 (♁). Antenna with 4 setae on exopod; allobasis with abexopodal seta. Mandibular palp elongate, 1-segmented; with one basal, one exopodal and 3 endopodal setae. Maxillule with defined exopod bearing 2 setae. Maxilla with 3 endites on syncoxa; endopod represented by 3 setae. Maxilliped elongate; syncoxa with 2 setae; basis without distinct ornamentation; endopodal claw long and curved, with one accessory seta.

P1 long, with elongate coxa and basis; with 2- or 3-segmented exopod, distal exopod segment with 2 short and 2 geniculate setae; endopod stout, enp-1 without inner seta, enp-2 with minute seta and long minutely denticulate claw. Swimming legs P2– P4 with 3-segmented exopods and 2-segmented endopods. P2–P4 exp-3 and P4 enp-2 without inner setae; inner seta of P4 enp-1 occasionally present in ♀ but always absent in ♁. P3 enp-2 produced into straight spiniform apophysis in ♁ (homologous with outer spine of enp- 2 in ♀). Inner distal seta of P2–P4 exp-3 reduced in ♁. Armature formula of swimming legs 2 to 4 (P2–P4) as follows:

P5 with separate exopod and baseoendopod. Exopod ovoid or elongate with 6 setae in ♀ and 4–5 setae in ♁. Endopodal lobe well developed in ♀, subtriangular, with 4–5 setae. Baseoendopods fused medially in ♁; endopodal lobes rudimentary, with 2 setae each.

P6 forming well developed operculum with 2 small setae in ♀; asymmetrical in ♁ (with dextral or sinistral configuration), with outer distal corner produced into process bearing 2 well developed elements.

Type species. Laophonte danversae Hamond, 1969 = Inermiphonte danversae ( Hamond, 1969) , comb. n.

Other species: Inermiphonte hamondi , sp. n.

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Species incertae sedis. Laophonte ? drachi Médioni & Soyer, 1966 = Inermiphonte drachi ( Médioni & Soyer, 1966) , comb. n.

Etymology. The generic name refers to the absence of inner setae on P2–P4 exp-3 and P4 enp-2 (Table 1). Gender: feminine.

Following Hicks’ (1982) comparative analysis Hamond’s (1969) “Laophontid male,?gen.,?sp.” is here assigned to a new species Inermiphonte hamondi , sp. n., which can be differentiated from the type species by the characters listed in Table 1 and Hicks’ (1982: 306) Table II. Laophonte ? drachi shows some important differences with the other two species such as the 6-segmented antennule in the female, the 2-segmented P1 exopod, the reduced inner distal setae on the female P2–P4 exp-3 (a character typical for male Inermiphonte ), and the presence of three strong spines on the male P4 endopod. L.? drachi resembles I. danversae in the presence of only one inner seta on P2 enp-2, no inner setae on ♁ P3 enp-2 and only three outer spines on P4 exp-3; it is similar to I. hamondi in the presence of only four elements on the male P5 exopod. It is here placed as species incertae sedis in Inermiphonte as I. drachi , comb. n.

Inermiphonte danversae is thus far known only from two localities in England. Hamond (1969) recorded three females from the shore at West Runton (Norfolk) and Hicks (1980, 1982) reported the species from a range of littoral algae in Robin Hood’s Bay (North Yorkshire) where it attained highest densities on Corallina officinalis L. and Cladophora rupestris (L.) Kutz. Inermiphonte hamondi and I. drachi are known only from their respective type localities, the former from the intertidal zone at West Runton ( Hamond 1969) where it may co-exist with I. danversae , the latter from colonies of the bryozoan Schismopora armata (Hincks, 1860) near Racou (Roussillon, France) ( Médioni and Soyer, 1966).