Dolops longicauda ( Heller, 1857 )

Tavares, Luiz E. R., 2017, A new species of Argulus (Crustacea, Branchiura, Argulidae) from the skin of catfish, with new records of branchiurans from wild fish in the Brazilian Pantanal wetland, Zootaxa 4320 (3), pp. 447-469 : 464-466

Dolops longicauda ( Heller, 1857)

( Figure 11 )

Gyropeltis longicauda HELLER, 1857 HELLER (1857): 101 –102, PL. I, fIGS. 1–19; Gyropeltis doradis , CORNALIA, 1860: CORNALIA (1860): 13 –14, fIGS. 1–18; G. longicauda : KRøyER (1863): 25 –28, PL. I, fIGS. 4A–E; G. longicauda AND G. doradis : THORELL (1864): 64; D. longicauda AND Dolops doradis : BOUVIER (1899): 13, 21–35, fIGS. 31–38; D. longicauda AND D. doradis : WILSON (1902): 704, 732–733, 734, PL. XV, fIGS. 75–76; D. longicauda : THIELE (1904): 14 –17, fIGS. 16–25; MOREIRA (1912): 149, PL. III, fIG. 3; MOREIRA (1913): 10, PL. V, fIG. 1; LAHILLE (1926): 11, fIGS. 8–9; LEMOS DE CASTRO (1985): 12, 56; THATcHER (2006): 393, 396, 400, fIG. 9.25.

Type host. Hydrocyon brevidens (= Salminus brasiliensis [Cuvier 1816]) ( Heller 1857)

Type locality. FLONA de Ipanema, Sorocaba River Basin, municipality of Iperó, region of Sorocaba, state of São Paulo, Brazil (see remarks)

Other hosts and localities. Aequidens tetramerus (Heckel, 1840) , Limoncocha, near the junction of the Jivino and Napo rivers, Ecuador ( Hugghins 1970), Igarapé Fortaleza, Amazon River Basin, Macapá, Amapá, Brazil (Tavares-Dias et al. 2014); S. brasiliensis (syn. S. brevidens , S. maxillosus , Salminus cuvieri , H. brevidens ), Province Entre Rios in Parana River Basin, Arroyo de las Conchas, Corpus, Rio Colastiné, Santa Fé, Zona de Rosario, in Uruguay River Basin, Gualeguaychú, Ibicuycito, Missiones, in de la Plata River, Argentina ( NMNH 2014; Ringuelet 1943, 1948), Paraguay River, Corumba, Cáceres, state of Mato Grosso, Pirassununga, Mogi Guaçu River state of São Paulo, Brazil ( Calman 1912; Morais Filho & Schubart 1955; Moreira 1912, 1913); Metynnis lippincottianus (Cope, 1870) , Igarapé Fortaleza, Amazon River Basin, Macapá, Amapá, Brazil (Tavares- Dias et al. 2014); Oxydoras kneri Bleeker, 1862 ( Ringuelet 1943) ; Oxydoras niger (Valenciennes, 1821) , Amazon River Basin, Brazil ( Bouvier 1899; Thatcher 2006); Potamotrygon sp., Santa Fe Province, Parana River, Rosario, Argentina ( Ringuelet 1948); P. corruscans , Santa Fe Province, Parana River, Rosario, Argentina ( Ringuelet 1948); Pterodoras granulosus (Valenciennes, 1821) ( Ringuelet 1943) ; S. maculatus, Caiçara bays, upper Paraguay River basin, Northern Pantanal, Cáceres, state of Mato Grosso, Brazil (Fontana et al. 2012); Serrasalmus nattereri (= P. nattereri ), Parana River, zona de Rosario, Argentina ( Ringuelet 1943); Serrasalmus sp., Limoncocha, near the junction of the Jivino and Napo rivers, Ecuador ( Hugghins 1970).

Material deposited. 21 vouchers: 5 adult female and 5 adult male ZUEC-CRU 3518, 5 adult female and 2 adult male INPA 2309, 6 July 2008; 2 adult females and 2 adult males MZUSP 36231, 8 July 2009, in ethanol 70%, Salminus brasiliensis , skin, Cuiabá River Cuiabá River, Parque Nacional do Pantanal Matogrossense, Mato Grosso, Brazil (17°49′37.77″ S, 57°22′53.38”W)

Measurements. Based on 6 males and 18 females. Total length (mm) 20.2 (13.5–25) in males, 22 (11.2–36.5) in females. Carapace length 7.7 (5.6–9.3) in males, 8.8 (5.7–13.7) in females; maximum carapace width 7.9 (4.6– 10) in males, 9.4 (6.1–15) in females. Carapace posterior sinus length 2.2 (1.1–3.3) in males, 3.2 (1.5–4.9) in females; width 2.2 (1.7–2.8) in males, 3.3 (1.8–6) in females. Cephalothorax length 4.7 (2.6–5.8) in males, 5.1 (3.1–8.2) in females; anterior width 4.6 (2.6–5.6) in males, 5.2 (4.3–7.3) in females. Abdome length 13.9 (9.6–18) in males, 12.9 (8.9–22) in females; width 3.3(2.1–3.9) in males, 3.8 (2.7–6) in females. Abdome posterior sinus length 11.8 (8.5–13.8) in males, 12.4 (4.7–20) in females; width 2.4 (1–3.4) in males, 2.8 (0.4–7.8). Eyes diameter (µm) left 274.5 (225–289) and right 283.4 (200–350), in male, left 267.8 (224–300) and right 278.4 (212–350) in female; transverse distance between eyes (µm) 2156.7 (1850–2768) in male, 2377.5 (1400–3651) in female. First maxillae length 2 (0.9–2.9) left and 2 (1–3) right in males, 2 (1.1–4.2) left and 2.3 (1.3–4.5) right in females; Hook of the first maxillae length (µm) 1072.5 (875–1300) left and 1156.6 (825–1300) right in males, 1281 (836.6–1450) left and 1366.5 (1019–1900) in females. Seta-like structure length (µm) 151 (129–178, n = 4) left and 170.8 (118.8–198, n = 4) right in males, 186.5 (138.6–243, n = 16) left and 201.7 (158.4–297, n = 16) right in females.

Remarks. The first and second antennae of D. longicauda are located in a groove in the cephalon, as others species of Dolops (Avenant et al. 1989; Silva-Souza et al. 2011). Nevertheless, the first antennae of D. longicauda is 4-segmented ( Fig. 11A ), a characteristic shared with some South American species of Dolops . The basal segment of the first antennae of D. longicauda does not have any projections or spines, being bar-shaped with expanded ends, which Ringuelet (1943) described as “…un refuerzo o rodete no saliente cerca del borde posterior…”. The proximal part of the second segment also does not have any projections or spines, similar to what we observed in D. carvalhoi . The labrum ( Fig. 11B ) in mouth tube in D. longicauda , and probably other species of the genus, arise anteriorly, deeper than in species of Argulus . The second maxillae of D. longicauda is 6-segmented ( Fig. 11C ). The sixth segment bears five pairs of hooks or claws ( Fig. 11D ), with the distal one the larger. These decrease proximally, so that the most proximal resemble spines.

Heller (1857) described D. longicauda when he proposed Gyropeltis Heller, 1857 , later synonymized with Dolops by Bouvier (1899). Before Bouvier’s observations, Krøyer (1863), examined the type specimen, a female deposited by Vincent Kollar at the Natural History Museum of Vienna, as “ Dixiphurus brasiliensis ”. An additional note on the type specimen in Johann Natterer's iternary revealed the old “Fábrica de Ferro São João do Ipanema” or Fundição Ipanema, nowadays a national forest known as FLONA de Ipanema, in the municipality of Iperó in the region of Sorocaba, in the state of São Paulo, as the type locality for this species (Peter C. Dworschak, pers. comm. March 2015). In this note by Natterer, a river called “Seruaba” was mentioned as the hydrographic system where the type specimen was recovered. Although we could not identify this river, it is probable that the Sorocaba River is the hydrographic basin of the type locality.

The morphology, the length and especially the length of the abdomen of the specimens of D. longicauda , made its diagnosis easier. Additionally, there is a structure similar to an additional flagella on the second leg of the male, inserted in the dorsal side of the coxa and laterally directed, which Ringuelet (1943) also indicated, removing any doubts about the identification of D. longicauda .

Figures

FIGURE 11. FEMALE Of Dolops longicauda. A fIRST (A 1) AND SEcOND (A 2) B MOUTH TUbE (LAbI: LAbIUM; LAbR: LAbRUM; M: MANDIbLES) C SEcOND MAXILLAE (SE: SENSILLUM; S 1 – 4: SEGMENTS) D fIfTH (S 5) AND SIXTH (S 6) SEGMENTS Of THE SEcOND MAXILLAE ANTENNAE E SETA-LIKE STRUcTURE (SLS) IN THE fIRTS MAXILLAE F ANAL PAPILLAE (VENTRAL VIEW). ScALE bAR = A 0.5 MM, B – C 0.25 MM, D – F 0.1 MM