Probosciphontodes, Fiers, 1988

Lee, Jimin & Huys, Rony, 2019, New Ancorabolidae (Copepoda: Harpacticoida) from Korea: two new genera, revisionary notes and updated identification keys, Zoological Journal of the Linnean Society 187, pp. 331-377 : 360-362

Probosciphontodes

* Type species.

a George’s (2006c: 164) original armature formula was corrected by Gheerardyn and George (2010).

b Although Gheerardyn & Lee (2012) considered the armature pattern of P3 enp sufficient evidence to rule out conspecificity with C. macropodia Gee & Fleeger, 1986 , it is conceivable that Brady’s (1918) illustration is incorrect in showing only two elements and depicting the ramus as one-segmented.

c Krishnaswamy (1957) illustrates three elements on exp-3 but states in the text that ‘… the third [segment] bears one outer spine and three apical setae’.

d Krishnaswamy (1957) states ‘Third and the fourth legs resemble the second one, the endopod of fourth leg however differs in having one apical and two inner setae’ but illustrates only P4 enp. It is questionable whether his observation of a one-segmented endopod in P2–P4 is correct, because within the genus this condition has so far been recorded only for P2–P 3 in La. brevis Gurney, 1944 (which was based on a juvenile; see Table 1). Pending a thorough redescription of the species and contrary to George & Gheerardyn’s (2015: 93) proposition, this character should not be used to differentiate La.ornatus from La. bicornis A.Scott, 1896 and/or La. horstgeorgei George & Gheerardyn, 2015 . Likewise, Arroyo et al. (2003) used it as a discriminant between La. ornatus and La. mourois Arroyo, George, Benito & Maldonado, 2003 . Given the contradictions between the text and illustrations and the deficiencies in the original description, it is recommended here to rank La. ornatus as species inquirenda in the genus.

e P2 endopod not discernible (‘missing or broken’) according to George (2018: 15).

f George & Gheerardyn (2015) recorded intraspecific variability in the presence/absence of the outer element, whereas Pallares (1975) observed specimens that lacked the inner element.

g Sars (1908) probably overlooked the rudimentary seta(e) on P1 enp-2 and misinterpreted the endopodal segmentation of P2–P4 (cf. Conroy-Dalton 2004: 28).

h Soyer (1975) figured a short seta along the distal inner margin of exp-3; comparison with Mielke’s (1981) detailed description of Pa. exopoditus shows that these ‘elements’ on P3–P4 are, in reality, long tube-pores (see his Abb. 59c–d). The presence of these setae was wrongly assumed by George (2017) in his phylogenetic analysis of Paralaophontodes . i Cottarelli & Baldari (1987: fig. 2F) show a long spinule at the inner distal corner, which they erroneously interpreted as a ‘short, latero-distal seta’.

of decomposed organic matter formed in stagnant conditions. Concurring with Cottarelli & Baldari (1987), Fiers (1988) also claimed a close relationship between these genera, because they differ from Laophontodes and Paralaophontodes by the absence of ornamentation on the dorsal surfaces of the body somites and by the much smaller bases in P2–P4. The first author to doubt the currently accepted taxonomic position of Patagoniaella was George (2006c: 169), who stated in a footnote that its type species ‘…presents several features making its affiliation to Ancorabolidae questionable’.

The major stumbling block to inclusion of Patagoniaella vervoorti in the Laophontodinae in particular appears to be the divergent morphology of its non-prehensile leg 1, an observation reiterated repeatedly in the recent literature ( Gheerardyn & George, 2010; Gheerardyn & Lee, 2012; George & Müller, 2013). In members of this subfamily, the outer spine of P1 exp-2 (or the proximalmost outer spine of exp-2 when the exopod is two-segmented; i.e. some species of Paralaophontodes, Tapholaopontodes and Ancorabolina George, 2006c ) is invariably modified into a geniculate seta, whereas in Patagoniaella vervoorti exp-2 has retained its bipinnate spine, which represents the plesiomorphic condition ( Gheerardyn & Lee, 2012). Likewise, in laophontodinids the P1 coxa has typically undergone secondary elongation along the proximodistal axis, but this apomorphic condition is not revealed in Pallares’ (1968) description (note also that as in most past descriptions, the coxa was only partly figured). Gheerardyn & George (2010) also identified a third apomorphy for the Laophontodinae that is not displayed by Patagoniaella , i.e. the presence of a spinular protuberance on the posterior margin of segment 2 of the antennule in both sexes. Finally, the leg 1 basis of Patagoniaella vervoorti shows moderate transverse elongation in the distal half but lacks the basal pedestal for the endopod, which, in combination with the three previous characters, precludes the species from being assigned to the Laophontodinae (see above).

The alternative option of transferring Patagoniaella to the Ancorabolinae is not justifiable because it would dramatically alter the diagnosis of the subfamily as evidenced by the following characters displayed by Patagoniaella vervoorti : (1) cephalothorax and free body somites without spinous projections (vs. present); (2) rostrum triangular, with apex not forming a ‘peak’ (vs. ‘peak’ present); (3) antennule ♀ five-segmented (vs. segments 3 and 4 fused to form a compound segment); (4) transverse elongation of P1 basis restricted to basal half only (vs. elongation involves allometric growth of the entire protopodal segment); and (5) P2–P4 exp-3 with three outer spines (vs. two outer spines). The quality of Pallares’ (1968) illustrations does not allow assessment of other characters, such as the presence of a middorsal tube-pore on pedigerous somites bearing P2–P5, which is found in all Ancorabolinae . However, it is obvious from the above that the genus Patagoniaella cannot be accommodated in this subfamily either and should therefore be excluded from Ancorabolidae .

Although a thorough analysis, at least at generic level, would be required to assess its position with more confidence, several morphological similarities suggest that Patagoniaella is related to members of Cletodidae . The short, five-segmented ♀ antennule, the moderate elongation of the bases and the segmentation/shape of the endopods of P1–P4, and the morphology of leg 5, with the long setophore carrying the outer basal seta, all indicate cletodid affinity. Pallares’ (1968: pl. 1, fig. 10) illustration of leg 1 of Patagoniaella vervoorti suggests the presence of setae with a brush-like tip on the endopod and exopod. Such penicillate setae have previously been reported in a number of cletodid genera (e.g. Stylicletodes Lang, 1936a ; Schizacron Gee & Huys, 1996 ; Strongylacron Gee & Huys, 1996 ; Triathrix Gee & Burgess, 1997 ; Spinapecruris Gee, 2001 ) and in some species of Enhydrosoma Boeck, 1873 (cf. Gee, 1994, 2001; Gee & Huys, 1996; Fiers, 1997; Gee & Burgess, 1997; Gómez, 2000, 2003). Based on this circumstantial evidence, Patagoniaella is here provisionally assigned to the Cletodidae .

TAXONOMIC NOTES ON LAOPHONTODES T. SCOTT, 1894

The taxonomic concept of Laophontodes has changed significantly since Schizas & Shirley (1994) listed 14 valid species in the genus. Lang (1965) had previously removed Laophontodes robustus BoŽić, 1964 to Paralaophontodes , and this course of action was repeated by George (2017), who moved Laophontodes armatus Lang, 1936c , Laophontodes hedgpethi Lang, 1965 and Laophontodes psammophilus Soyer, 1975 to the same genus. Conroy-Dalton & Huys (2000) transferred the inadequately described Laophontodes echinatus Brady, 1918 as species inquirenda to Breviconia Conroy-Dalton & Huys, 2000 . Laophontodes expansus Sars, 1908 was subsequently placed in the new genus Lobopleura by Conroy-Dalton (2004), and Gheerardyn & Lee (2012) proposed Calypsophontodes to accommodate two (subAntarctic) species, Laophontodes macropodia Gee & Fleeger, 1986 and Laophontodes latissimus Brady, 1918 (the latter as species inquirenda). Although the genus Laophontodes saw the addition of eight new species in recent years ( Arroyo et al., 2003; Kornev & Chertoprud, 2008; George & Gheerardyn, 2015; George, 2018) it is known that other as yet unidentified or undescribed species have been recorded from the Thames estuary in England ( Attrill, 1998), Galicia in Spain ( Miranda et al., 1999), Pulia ( Moscatello & Belmonte, 2007) and Sardinia ( Noli et al., 2018) in Italy, the Great Meteor Seamount in the subptropical North Atlantic ( George & Schminke, 2002), Zanzibar ( Gheerardyn et al., 2008), the Clarion-Clipperton zone in the tropical Eastern Pacific ( Amon et al., 2017), New Zealand ( Hicks, 1977), the South Shetland Islands ( Hong et al., 2011; Bick & Arlt, 2013), South Georgia ( Dartnall, 2005), the Straits of Magellan ( George, 2005) and Washington State ( Toft et al., 2010). Although George & Gheerardyn (2015) provided an updated generic diagnosis for Laophontodes , they cursorily expressed their dissatisfaction about the current inclusion of a number of species. Below, we provide justification for the exclusion of two of them, Laophontodes gracilipes Lang, 1936b and Laophontodes multispinatus Kornev & Chertoprud, 2008 .