Paramoera falklandica, Vader & Krapp, 2005
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publication ID |
https://doi.org/ 10.1080/00222930500218573 |
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persistent identifier |
https://treatment.plazi.org/id/03E98010-570C-D919-FE35-FC946090FC71 |
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treatment provided by |
Felipe |
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scientific name |
Paramoera falklandica |
| status |
sp. nov. |
Paramoera falklandica View in CoL n. sp.
( Figures 10–12 View Figure 10 View Figure 11 View Figure 12 )
Type material
Holotype: ovigerous female 9 mm, in alcohol. East Falkland, Choiseul Sound, 30 m, from Paralomis granulosa and Eurypodius latreillei , caught in baited traps, 29 October 2003, A. and W. Vader leg. Deposited at TromsØ Museum no. 13846. Paratypes: one male 9 mm, 16 smaller specimens in alcohol, two slides ovigerous female and two slides male, same locality. Deposited at TromsØ Museum no. 13847.
Additional material
Seven specimens, Lively Sound, E. Falklands, March 2003, A. Vader, from Paralomis ; 61 specimens, Lively Sound , East Falkland, 15 April 2003, A. Vader, from Paralomis bins ; 11 specimens, Lively Sound , East Falkland, 3 May 2003, A. Vader, from ‘‘spider crabs’’, a few from bins ; 292 specimens, Choiseul Sound , East Falkland, 29 October 2003, A. and W. Vader, from crab bins ; 15 specimens, Choiseul Sound , East Falkland, 29 October 2003, A. and W. Vader, from Paralomis granulosa .
Type locality
Choiseul Sound, East Falkland, from Paralomis .
Diagnosis
A slender and colourful Paramoera species , with the almost unique combination of a small posterodistal tooth on epimeral plate 3, and a telson with only distal setae.
Description
Male and ovigerous female both 9 mm. Body: dorsally smooth. Head: rostrum very short, lateral cephalic lobe blunt; eyes large, rounded with many well-developed ommatidia. Epimeral plates 2–3 with small posterodistal tooth.
Antennae: A1.A2. A1 long, flagellum with 35 articles; peduncle much shorter than flagellum, with article 1.2.3, sparsely setose; accessory flagellum tiny, one-articulate. A2 also long, flagellum with 45 very short articles; peduncle articles 4 and 5 subequal, sparsely setose.
Mouthparts: labrum rounded. Mandible with incisor process strong, accessory processes well developed, lacinia mobilis trifurcate; molar trituritative, strong, surrounded with stiff setae; palp strong, three-articulate, with article 3 subequal to 2, rounded, with a fringe of equal-sized comb-shaped D-setae and longer distal E-setae. Maxilla 1 inner plate with four stout pappose setae, outer plate with 9–11 pectinate spines; palp two-articulate, article 2 rounded, with a ‘‘crown’’ of seven short and five long robust setae and two longer marginal setae. Maxilla 2 inner plate with oblique row of six long plumose setae medially and simple shorter setae distally, outer plate with rows of plumose and simple setae. Labium: inner lobes present, small. Maxilliped: inner plate reaching but not surpassing article 1 of palp, outer plate reaching end of article 2 of palp; palp with four articles, outer margin scarcely setose, inner one with regular simple setae; article 1 outer margin distally scarcely lengthened, article 1 twice as long as article 2, article 3 distally lobed, with group of long and short setae; dactylus smooth, insertion subdistally on article 3, surpassed by lobe.
Gnathopods: alike, but sexually diverse, medium, Gn2 longer than Gn1. Gn 1 female: coxa anterodistally slightly expanded, distal margin vaguely crenulate, with minute posterodistal tooth in male; ratio coxa: propodus52; basis long, narrow, with groups of short setae; carpus almost as long as propodus, with two large groups of setae on hind margin; propodus narrow, with parallel sides and groups of setae on hind margin, ratio length: breadth is 2.25; palm almost transverse, somewhat convex, almost smooth but palmar angle with two robust setae; dactyl as long as palm, smooth. Gn 1 male: carpus and propodus much stronger, ratio coxa: propodus51.2; propodus clearly longer than carpus. Gn 2 in both sexes similar to Gn1, but almost twice as large. Gn 2 female propodus twice as long as propodus Gn1; coxa with parallel margins, anterior margin slightly rounded; basis long, with short setae on posterior margin; carpus triangular, longer than broad; propodus clearly much larger than carpus, with parallel sides and five to seven groups of setae on hind margin. Palm almost transverse, slightly convex, almost smooth but row of fine setae subdistally, palmar angle with a group of three robust setae. In females, where the body is much more depressed than in males, both gnathopods are more and more twisted with age, so that the propodus is held not vertically, but parallel to the body, with its surface carried horizontally. Gn 2 male propodus about twice as long as Gn1, similar to female.
Peraeopods: P3 coxa as in Gn2, basis narrow, merus as long as carpus, almost unexpanded distally, ratio propodus: carpus51.5, propodus unexpanded distally; dactylus strong, falcate. P4: coxa broad, longer than broad, as deep as coxa 2–3, with shallow posterior emargination; basis and merus narrow, merus with slight distal lobe; propodus longer than carpus. P5–7: basically similar, same size as P3–4; coxae short; basis broadly expanded, with posterior expansions smooth, merus distally somewhat lengthened, propodus. carpus, ratio51.5–1.6; dactylus strong, falcate. In P7 distal robust setae on propodus give a hint of ‘‘subchelate pereopod’’.
Uropods: U1 slender, peduncle longer than rami; peduncle with three to seven marginal and two distal robust setae, rami with four lateral plus a group of distal robust setae; outer ramus slightly shorter than inner. U2: slender, with peduncle shorter than rami; outer ramus ca half the length of inner; peduncle with two marginal robust setae, inner (longer) ramus with four to five robust setae on both margins, outer ramus with two to three, both rami with group of distal robust setae. Ratio U2:U351.2; U3 peduncle short, naked, with a distal lobe; rami with marginal spines on both margins, outer ramus ca 80% of inner.
Telson short, cleft ca for half its length. Apices of distal lobes incised and bifurcate, with a short seta in the indentation, telson otherwise naked.
Gills on P2–7, oostegites on P2–5.
Colour in life. Very colourful and individually variable, with different types of chromatophores: scattered fields of superficial black ones and much denser fields of white ones. In addition there is a more diffuse red pigment, that in some specimens completely dominated, while in others it was largely absent. The eyes were red with a white ‘‘coating’’. As an example one specimen had chalk-white fields of chromatophores on the peduncles of A1–2, laterally on the metasome segments, and dorsally on the head, mesosome segments 4, 5–6 (a large patch) and 7, with smaller white patches distally on the metasome segments. In addition, as was the case in many specimens, the bases of P5–7 were all-white, with smaller patches on merus and ischium, while the distal articles were almost colourless. But, as said, every specimen had a somewhat different colour pattern; furthermore the chromatophores are probably able to contract and expand in fresh animals.
Etymology
The adjective ‘‘ falklandica ’’ is chosen on account of the locality of the collection.
Discussion
‘‘The identity of various species of Paramoera is so confounded presently that I cannot properly evaluate variables within that genus’’, wrote Barnard in 1972, and Thurston (1974) who, at the same time as Bellan-Santini and Ledoyer (1974), made valiant efforts to create some order, added: ‘‘The taxonomy and distribution of species of Paramoera in Antarctic and sub-Antarctic regions has been complicated by the number of species involved, the lack of adequate descriptions of many of them and the sweeping synonymies assumed for several of the poorly known species described in the nineteenth century.’’ Barnard and Karaman (1991) recognized 39 described species plus some 10–15 evidently misidentified entities. In this paper we have primarily compared our material with the ca 27 species described from southern waters (for the authors’ names see Barnard and Karaman 1991, p 332).
In the initial sorting we used two main criteria, the form of the third epimeral plate and the presence or absence of lateral setae on the telson.
The third epimeral plate comes in two quite clearly separated different forms in Paramoera . Many species have a rounded epimeral plate, usually with a more or less clearly serrulated posterior margin: P. australis , P. austrina auct., P. brachyurus , P. chevreuxi , P. hamiltoni , P. hermitensis , P. hurleyi , P. pfefferi , P. rangitiva , P. schellenbergi , P. tristanensis , and ‘‘ P. fissicauda ’’ (sensu Bellan-Santini and Ledoyer 1974)—we were unable to establish the form in P. macquariae and P. willisi . Paramoera husvikensis has a ‘‘broadly angular’’ Ep3, but all the other species: P. assimilis , P. capensis , P. edouardi , P. fasciculata , P. gregaria , P. kergueleni , P. obliquimanus , P. parva and P. stephenseni have, just as the present material, a third epimeral plate with a small posterodistal tooth.
A few of these species have special features that make it clear that they are specifically different from the Falkland specimens: P. obliquimanus and P. parva have very characteristically formed gnathopods, as in a slightly different way have P. fasciculata and P. rangitiva . Paramoera brachyurus and P. stephenseni (originally also described as P. brachyura ) have a strangely shortened uropod 2, and P. bidentata has dorsal teeth.
The second criterion we used in sorting was the presence or absence of lateral setae on the telson. The following species have, as do the Falkland specimens, only distal setae: Paramoera assimilis , P. australis , P. hermitensis , P. pfefferi , and P. tristanensis ; P. hamiltoni , P. hurleyi , and P. rangitiva have only very small setules laterally, so are close to this character state. All these species, except P. assimilis , have a rounded Ep3, and it is therefore only P. assimilis ( Stebbing, 1888) that has the same combination of toothed Ep3 and a telson with distal setae only. Paramoera assimilis , found as a single specimen off the coast of South Africa, differs from P. falklandica in the configuration of the peduncle of A1 and the much stronger, though also uniarticulate, accessory flagellum. A number of Paramoera species have been reported from the Falkland Islands, generally from shore-collecting ( Schellenberg 1931; Barnard 1932); somewhat unexpectedly, none of them is identical to the present material of a species, that apparently lives in large numbers at 20–40 m in Choiseul Sound. As we had no opportunity to carry out general collecting in the area, it is uncertain whether the present species really is an obligate associate of large decapods. Most Paramoera species seem to be generalists, occupying shore habitats in the cold Antarctic waters seasonally, and in more temperate waters year-round: a few have been collected subtidally. There are no earlier records of symbiotic associations.
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