Lernaeopoda sp.

Montes, Martin M., Gómez, Sebastián, Castro, Raúl R., Bovcon, Nelson, Vettorazzi, Renzo I., Serrano, Claudio F., Reig Cardarella, German F., Ferrari, Walter, Cuevas, Juan Martin & Martorelli, Sergio R., 2023, How many species of genus Lernaeopoda Blainville, 1822 (Siphonostomatoida: Lernaeopodidae) are there in the southwestern Atlantic?, Zootaxa 5346 (4), pp. 469-488 : 475-478

Lernaeopoda sp. (X4)

Figs. 2D and 6

Host: Schroederichthys bivius Müller & Henle, 1838

Site of infection: palate inside the mouth.

Locality: Rawson, Buenos Aires, Argentina (discarded from fisheries)

Material examined: 1 ovigerous ♀♀,

Voucher material: One adult (ovigerous) female specimen XXXX deposited in the Invertebrate Collection of Museo de La Plata, Buenos Aires, Argentina.

Description of adult females by optical microscopy (OM) (measurements in Table 3 ): Short cephalothorax, dorsoventrally flattened, inclined ventrally to long axis of trunk, conforming to “ Type A” structural plan ( Kabata 1979). Dorsal shield of cephalothorax visible (but not distinct) laterally, dorsal margin rounded. Cephalothorax clearly delimited from trunk. Trunk rectangular, posterolateral margins rounded, with median anal slit on posterior margin elevated on tubercle, flanked by uropods (according to Kabata 1979). Uropods fusiform. Egg sacs multiseriate (not measured).

Antennule ( Figs. 3A , 4A , 5A , 6A ) 4-segmented (3-segmented in X4), basal segment inflated, with long whip (in X1 and X4), or whip on second segment (X2), solus not observed or small solus on third segment (in X3), distal segment armed with seta 1, 4 (in X1, X2, X3, X4), seta 5 trifid (in X1) or bifid (in X2, X3, X4), tubercle 3 (in X1, X2, X3), seta 6 flagelliform and seta 2 flagelliform (in X4).

Antenna ( Fig 3B , 4B , 5B , 6B and details) 1-segmented, bulbous, exopod, larger than endopod, without elements or with papillae bearing spines on ventral surface of both segments (only in X2), Endopod reduced, 2-segmented, with proximal segment bearing ventral pad of denticles, distal segment with one robust seta 1, and two spiniform setae (5 and 2), ventrally with elements less clearly discernible, or pad of four denticles (only in X1).

Mandible ( Fig. 3C , 4C , 5C , 6C ) dental formula: P1, S1, P1, S1, P1, S1, B4 or B5 (only in X3).

Maxillule bilobate ( Fig. 3D , 4D , 5D , 6D ), palp bearing two short apical setae; endite with three papillae distally, each one bearing seta, and with spinules near base of setae.

Maxillae cylindrical, slightly tapering toward tips, expanded at tips, each maxilla separate, united only at bulla, bulla with short manubrium, anchor not observed.

Abreviattions: NS= not specified; S= solus; W= whip

Abreviations: seg= segments

Maxilliped ( Fig. 3E , 4E , 5E , 6E and details) with long strong corpus or more slender (only in X4) and short subchela; myxal area with denticulate pad; another denticulate pad (rod denticles) distally at base of subchela; third denticulate pad distally on inner margin (in X1) without spine or, if present, outside pad (pad armed with spine on papilliform process in X2, pad subquadrangular in X3; spine far from pad in X4). Annexed barb tapering, reaching about 1/4 (in X1), 1/3 (in X3 and X4) and 1/2 (in X2) length of claw; latter slightly curved, tapering with blunt tip, two secondary teeth at level of barb (in X1, X3); third tooth on tip of claw (in X2)

Figures

FIGURE 2—Females of Lernaeopoda sp. A—with “short” maxilla (X1), from fins of Galeorhinus galeus. B—from palate of Schroederichthys bivius (X2). C—with “short” maxilla, from cloaca of Schroederichthys bivius (X3). D—with “long” maxilla, from palate of Schroederichthys bivius (X4). Scale Bars: A, B, D= 2 mm, C=1 mm.

FIGURE 3—Appendages of the Lernaeopoda sp. (X1) female on fins of Galeorhinus galeus. A—Antennule. B—Antenna and detail of endopod C—Mandible. D—Maxillule. E—Maxilliped and detail of claw, myxal area and pad of spinules. Abbreviations: Ab = Annexed barb, Cl = claw, Co = corpus, Dp = Denticles Pad, E = endite, En = endopod, Ex = exopod, P = palp, Rd = Rod denticles, sp = spines on maxilliped, w = Whip, 1, 2, 3, 4, 5, 6 = Armature. Scale Bars A = 50 µm. B = 100 µm. C = 25 µm, D = 25 µm, E = 200 µm.

FIGURE 4—Appendages of the Lernaeopoda sp. (X2) female with “short” maxilla, on palate of Schroederichthys bivius A—Antennule. B—Antenna. Detail of endopod and armature. B1—Other view of the endopod. C—Mandible. D—Maxillule. E—Maxilliped and detail of claw, myxal area and pad of spinules. Abbreviations: Ab = Annexed barb, Cl= Claw, Co = Corpus, Dp = Denticle pad, E= Endite, En = Endopod, Ex = Exopod, P= Palp, Rd = Rod denticles, s = Spine, So = Solus, Sp = Spines on maxilliped, w=Whip, 1, 2, 3, 4, 5, 6 = Armature. Scale bars A and B =100um, C = 50, D = 25, E = 100.

FIGURE 5—Appendages of the female Lernaeopoda sp. (X3) from Schroederichthys bivius cloaca with “short” maxilla. A—Antennule. B—Antenna and detail of endopod armature. C—Mandible. D—Maxilulle. E—Maxilliped and details of claw, myxal area and pad of spinules. Abbreviations:Ab = Annexed barb, Cl = Claw, Co = Corpus, D = denticle, En = endopod, Ex = Exopodo, E = endite, P = palp, Rd = Rod denticles, S = Spine, So = Solus, Sp = spines on maxilliped, w = Whip, 1, 2, 3, 4, 5, 6 = Armature. Scale Bars: A = 50 µm, B= 200 µm, C = 25 µm, D = 25 µm, E = 25 µm.

FIGURE 6—Appendages of the female Lernaeopoda sp. (X4) from Schroederichthys bivius palate with “long” maxilla. A— Antennule and detail of distal armature. B—Antenna and detail of endopod and its armature C—Mandible. D—Maxilulle. E—Maxilliped and details of claw, myxal area and pad of spinules.Abbreviations:Ab = Annexed barb, Cl= Claw, Co = Corpus, Dp = Denticle pad, E = Endite, En = Endopod, Ex = Exopod, P = Palp, Rd = Rod denticles, s = Spine, Sp = Spines on maxilliped, w =whip, 1, 2, 3, 4, 5, 6 = Armature. Scale Bars: A=50 µm, B=100 µm, C=100 µm, D= 50 µm, E =50 µm.