Asymmetrione aequalis, Pardo & Boyko & Mantelatto, 2009
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publication ID |
https://doi.org/ 10.1080/00222930903094639 |
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persistent identifier |
https://treatment.plazi.org/id/664D87EB-FF9C-5056-FC9F-76519537FBA6 |
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treatment provided by |
Felipe |
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scientific name |
Asymmetrione aequalis |
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Suborder EPICARIDEA Latreille, 1831
Family BOPYRIDAE Rafinesque-Schmaltz, 1815 Subfamily PSEUDIONINAE Codreanu, 1967 Genus Asymmetrione Codreanu, Codreanu and Pike, 1965 Asymmetrione aequalis n. sp.
Material examined
Holotype: female (9.0 mm) and allotype male (3.1 mm) ( MZUSP 18,339 View Materials ).
Type locality
Off Isla La Vieja, Bahía Independencia , Reserva Nacional de Paracas, Pisco, Peru (14°15´48.36″S, 76°11´46.4″W) GoogleMaps .
Description of holotype
Female outline ovoid, body margins slightly distorted dextrally (≈10°) ( Figure 1A–B View Figure 1 ); total length 9.0 mm, maximal width at third pereomere; antennae, antennules and pereopods visible in dorsal view; head distinct from first pereomere, broader than long, surface smooth, front with broad lamina, eyes and pigmentation absent; anterolateral corners of head sharply angled. Maxilliped distally tapering, palp lacking, spur long and narrow ( Figure 2C View Figure 2 ). Antennule 3 – segmented ( Figure 2A View Figure 2 ); basal segment subquadrate, lacking setae; second segment subcylindrical with subapical setae; third segment ovate, smaller, tuft of short setae on tip. Antenna 5 – segmented ( Figure 2B View Figure 2 ); basal segment quadrate, lacking setae; segments 2–4 subcylindrical, distal segments progressively narrower, segment 2 distalmost with ring of distal setae, terminal segment minute, tuft of small setae at tip ( Figure 2A View Figure 2 ); barbula formed by pair of acute, distally recurved lateral smooth projections; central region with undulating margin ( Figure 2D View Figure 2 ). Pereomeres dorsally, ventrally and laterally distinct; pereonites 1–4 with well-developed coxal plates and large dorsolateral bosses; pereonites 5–7 with weakly-developed coxal plates and lacking bosses ( Figure 1A View Figure 1 ). Oostegites fully enclosing brood pouch ( Figure 1B View Figure 1 ); first oostegite 2 – segmented ( Figure 2E View Figure 2 ), covering head and forming anterior part of brood pouch, external surface smooth; anterior segment subtriangular, slightly more than 1.5-times as long as tapered posterior segment, which is approximately as wide as high, with posteriorly-directed thin digitate lobe; inner surface concave in both segments; oostegites 2–5 large and ovate, increasing in size posteriorly; fifth oostegite with posterior marginal fringe of setae ( Figure 2I View Figure 2 ), extending across posterior border of marsupium and overlapping opposite oostegite. Pereopods similar but progressively smaller posteriorly ( Figures 2F–H View Figure 2 ), bases wide and rectangular, ischia cylindrical with slightly crenulated ventral edge, meri subquadrate, carpi conical, propodi swollen distoventrally with deep socket present; dactyli strongly recurved. Pleon approximately 30% as long as head/pereon ( Figure 1A View Figure 1 ); five pleomeres dorsally and laterally separated, pleotelson bilobed; pleomeres laterally rounded without lateral plates; five pairs of biramous elongate, swollen pleopods, endopods and exopods both well developed ( Figure 1A–B View Figure 1 ); margins of pleopods smooth with surfaces sparsely covered in large swollen tubercles ( Figure 2J View Figure 2 ), uropods uniramous, similar in shape but smaller than pleopods, with swollen tubercles ( Figure 2K View Figure 2 ).
Male ( Figure 3A–B View Figure 3 ). Body generally unpigmented with few small spots on anterolateral margins of pereomeres, body elongated, all segments clearly segmented dorsally, ventrally and laterally; head suboval, distinct from first pereomere; approximately 1.7-times as wide as long; anterolateral borders rounded, head approximately 70% as wide as first pereomere; eyes present mediolaterally; antennule of three articles, antenna of seven articles, both distally setose ( Figure 3C–D View Figure 3 ). Pereomeres not widely separated, maximal width at third and fourth pereomeres, tapering anteriorly and posteriorly; midventral tubercles absent; generally isomorphic pereopods but progressively smaller dactyli and propodi and larger ischia posteriorly ( Figure 3B, E–G View Figure 3 ). Pleon with five segments plus pleotelson. Pleomeres progressively narrower posteriorly, distinctly separated, tips rounded; globose uniramous pleopods on pleomeres 1–5 near midline ( Figure 3B, H–I View Figure 3 ); pleotelson produced in two tapered lateral lobes and prominent medial anal cone, small tuft of setae on distolateral tips of projections; uropods absent ( Figure 3J View Figure 3 ).
Etymology
This specific name refers to the lack of dramatic asymmetry in females of this species that is, except in A. foresti , otherwise characteristic of the species in the genus.
Remarks
Markham (2003) listed seven genera of branchial parasitic bopyrids from hermit crab species ( Diogenidae , Paguridae and Parapaguridae ), but currently there are eight including Bopyrophryxus Codreanu, 1965 ( Bourdon and Boyko 2005). In only one of these eight genera are the propodi of the female’s pereopods modified into “sockets” for insertion of the dactyli, and so we must assign this new species to Asymmetrione . The near total lack of asymmetry of the female reported here does not in itself preclude inclusion of the species in Asymmetrione . In fact, the genus Megachelione Bourdon, 1968 , with sole species M. foresti Bourdon, 1968 , was synonymized with Asymmetrione by Markham (1975) after determination that the only character separating these two genera was the degree of asymmetry of the females. In all respects, including the limited asymmetry, the new species described here resembles A. foresti . It can be separated from A. foresti by the shape of the female head (ovate in A. foresti vs. distinctly wider than long in A. aequalis ), development of the female pereon coxal plates (well developed on pereomeres 1–4 with incomplete plates on 5 and 6 in A. foresti vs. pereomeres 1–4 only in A. aequalis ), and female pleomere lateral plates (well developed on pleomeres 1–5 in A. foresti vs. lacking in A. aequalis ), as well as the size of the anal cone in males (subequal to pleotelson posterolateral projections in A. foresti vs. much shorter than pleotelson posterolateral projections in A. aequalis ). Although Markham (1975) stated that A. desultor Markham, 1975 , was similar to A. foresti , the present species is much more so. A key is given below to facilitate the separation of the females of the 10 species of Asymmetrione now known. In many cases, the males are either not described in enough detail or lack obvious characters to separate them easily, although some species (e.g., A. clibanarii ) are quite distinct from others. Although the males can be difficult to separate, their uniformity in almost all characters (except for the number of antennal segments and pleotelson/uropod or posterolateral projection ratios) supports the inclusion of all 10 species in Asymmetrione , as does the shared character of the propodal “socket” in females.
Key to females of Asymmetrione species
1. Greater than 50° body asymmetry................................. 2 Less than 50° body asymmetry................................... 7
2. Barbula finely digitate on margins................................ 5 Barbula otherwise............................................. 3
3. Pleopods tuberculte...................... A. nossibensis Bourdon, 1976 Pleopods View in CoL smooth.............................................. 4
4. Lateral plates on pleomeres 1–3............. A. clibanarii Markham, 1975 Lateral View in CoL plates on pleomeres 1–5... A. sallyae Williams and Schuerlein, 2005 View in CoL
5. Uropods uniramous............................................ 6 Uropods biramous......................... A. dardani Bourdon, 1968 View in CoL
6. Second oostegites dissimilar............... A. asymmetrica (Shiino, 1933) Second View in CoL oostegites similar.... A. shiinoi Codreanu, Codreanu and Pike, 1965 View in CoL
7. Uropods uniramous............................................ 7 Uropods biramous............................................. 8
8. Lateral plates lacking on pleomeres 1–5................ A. aequalis View in CoL n. sp. Lateral plates present on pleomeres 1–5........ A. foresti (Bourdon, 1968) View in CoL
9. Oostegite 1 posterior region> anterior † ... A. ambodistorta Markham, 1985 Oostegite View in CoL 1 regions subequal † ................ A. desultor Markham, 1975 View in CoL
†The relative size of the regions in dorsal view.
Remarks on the Bopyridae of the southeastern Pacific
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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