Ceratothoa oxyrrhynchaena Koelbel, 1878

Martin, Melissa B., Bruce, Niel L. & Nowak, Barbara F., 2013, Redescription of Ceratothoa carinata (Bianconi, 1869) and Ceratothoa oxyrrhynchaena Koelbel, 1878 (Crustacea: Isopoda: Cymothoidae), buccal-attaching fish parasites new to Australia, Zootaxa 3683 (4), pp. 395-410 : 401-406

Ceratothoa oxyrrhynchaena Koelbel, 1878

Figures 4–6

Ceratothoa oxyrrhynchaena Koelbel, 1878: 401 , pl. I, fig. 1 (a–e).— Gerstaecker, 1901: 261.— Avdeev, 1982a: 65; 1982b: 69.— Rokicki, 1984: 132, fig. 33; 1985: 95, tab. 1–3, fig. 6.— Trilles, 1986: 624, tab. 1; 1994: 124; 2008: 23.— Trilles, Radujković and Romestand, 1989: 292, fig. 10.— Horton, 2000: 1045, fig. 5 (a–b).— Huang, 2001: 325.— Yu and Li, 2003b: 267.— Bariche and Trilles, 2005: 5.— Ramdane, Bensouilah and Trilles, 2007: 67.—Pérez-del Olmo, Fernández, Gibson, Raga and Kostadinova, 2007: 152.— Ramdane and Trilles, 2008: 173.— Yamauchi, 2009: 468, figs. 1–2.— Yamauchi and Nunomura, 2010: 72, figs. 3–6.

Cymothoa oestroides .— Bullar, 1878: 505, pl. 47, figs. 21–22.

Ceratothoa oxyrrhynchoena [lapsus].— Schioedte and Meinert, 1883, 368, tab. XVI (Cym. XXIII) figs. 10–14.

Meinertia oxyrrhynchaena .— Thielemann, 1910: 36 –38, 98–99, figs. 35–36.— Nierstrasz, 1915: 89.— Gurjanova, 1936: 84.— Montalenti, 1948: 51, figs. 18–21, tab. 7, pl. 5.— Euzet & Trilles, 1961: 190.— Quintard-Dorques, 1966: 10 –11.— Trilles & Raibaut, 1971: 74, photo 4.— Trilles, 1972a: 1208, figs. 137–155, pl. 1 (9), pl. 2 (13–14), pl. 3 (21); 1972b: 1250; 1977: 10.— Dollfus & Trilles, 1976: 824.— Capapé & Pantoustier, 1976: 201.— Avdeev, 1978a: 30.— Moreira and Sadowsky, 1978: 100, 111, 113–114, 116, 120.— Yamaguchi, 1993: 193, fig. 20.

Meinertia oxyrhynchaena [lapsus].— Komai, 1927: 1148, fig. 2215; Iwasa, 1947: 816.

Codonophilus oxyrhynchaenus [lapsus].— Nierstrasz, 1931: 132.— Saito, Itani and Nunomura, 2000: 65.— Tatsu, 2002: 41.

Ceratothoa oxyrhanchaenus [lapsus].— Nunomura, 2006: 36.

Not Cymothoa oestroides .— Bullar, 1878: 505.

Not Meinertia oxyrhynchaena [lapsus].— Yamaguti, 1938: 27.— Iwasa, 1947: 816.

Not Codonophilus oxyrhynchaenus [lapsus].— Shiino, 1965: 544. [= Elthusa Schioedte and Meinert, 1884 ].

Not Ceratothoa oxyrrhynchaena .— Bruce, 1982: 320, figs. 3 (a–k), figs. 4 (d–h).— Yu and Li, 2003a: 224 –227, fig. 2.

Material examined. Ƥ (20 mm ovig., dissected), trawled M.V. “Karumba Pearl” off Mackay, QLD, 21º42’S; 152º55’E, April 1988, from buccal cavity of Dentex spariformis Ogilby, 1910 , coll. Raptis Seafood (MTQ W15730).

Swains Reef, Queensland series: 4 Ƥ (18–19 mm), stn QLD– 1251, 139 m, on FV "Seadar Bay", 22°26.75'S; 153°07.17'E, 8 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49003). 13 Ƥ (14–25 mm), stn QLD– 1254, 181 m, on FV "Seadar Bay", 22°11.55'S; 153°11.72'E, 9 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49004). 8 Ƥ (17–19mm), stn QLD– 1255, 181 m, on FV "Seadar Bay", 22°25.00'S; 153°20.39'E, 9 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49005). 5 Ƥ (14–19 mm), stn QLD– 1256, 199 m, on FV "Seadar Bay", 21°59.43'S; 153°06.60'E, 10 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49006). 3 (14–19 mm), stn QLD– 1257, 199 m, on FV "Seadar Bay", 21°50.99'S; 153°01.39'E, 10 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49007). 2 Ƥ (17, 17 mm), stn QLD– 1258, 179 m, 21°43.23'S; 152°57.06'E, on FV "Seadar Bay", 10 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49008). 2 Ƥ (17, 17 mm), stn QLD– 1260, 179 m, 21°50.16'S; 152°57.14'E, on FV "Capricorn 1", 11 September 1995, coll. J. K. Lowry and K. Dempsey (AM P49009). 1 Ƥ (18 mm), stn QLD– 1267, 201 m, on FV "Capricorn 1", 21°45.18'S; 152°58.25'E, 14 September 1995, J. K. Lowry and K. Dempsey (AM P49010).

Ovigerous female. Length 20 mm, width 9 mm.

Body ovoid, 2.2 times as long as greatest width, smooth and polished in appearance, widest at pereonite 5, narrowest at pereonite 1, lateral margins posteriorly ovate. Cephalon 0.6 times longer than wide, visible from dorsal view, subacute. Frontal margin subacute, simple. Eyes well-developed, 0.2 times width of head. Pereonite 1 smooth, anterior border slightly concave, anterolateral angle produced and rounded, reaching anterior region of eye. Coxae 2–7 with posteroventral angles rounded. Pereonites 5 to 7 progressively narrower in length, posterior margins smooth and straight. Pleonites visible in dorsal view; posterior margin smooth, mostly concave; posterolateral angles of pleonite 2 narrowly rounded, extending posteriorly to anterior of pleonite 4; pleonite 5 with posterolateral angles free, not overlapped by lateral margins of pleonite 4, posterior margin straight. Pleotelson 0.3 times as long as anterior width, lateral margins convex, posterior margin weakly concave, without median point.

Antennule more stout than antenna, comprised of 7 articles; peduncle articles 1 and 2 distinct and articulated; article 2 0.4 times as long as article 1; article 3 0.3 times as long as combined lengths of articles 1 and 2, 0.6 times as long as wide; extending to posterior margin of eye. Antenna comprised of 9 articles; peduncle article 3 1.1 times as long as article 2, 1.0 times as long as wide. Article 4 1.0 times as long as wide, 1.0 times as long as article 3. Article 5 0.7 times as long as article 4, 1.1 times as long as wide; last article terminating in no setae, extending to posterior margin of head. Labrum lateral margins concave, anterior margin acute, without small median point. Mandibular process ending in acute incisor, mandible palp article 2 and 3 with fine ‘pectinate scales’; article 3 with 5 slender spines. Maxillule simple with 4 terminal robust spines. Maxilla mesial lobe with 10 recurved spines, partly fused to lateral lobe with 3 recurved spines. Maxilliped oostegite lobe lamellar. Maxilliped article 3 with 5 curved spines. Oostegite smooth, with setae.

Pereopod 1 basis 1.3 times as long as greatest width; ischium 0.7 times as long as basis; merus proximal margin with bulbous protrusion; carpus with rounded proximal margin; propodus 1.7 times as long as wide. Pereopod 2 propodus 1.5 times as long as wide; dactylus 1.2 times as long as propodus. Pereopod 6 basis 1.2 times as long as greatest width, ischium 0.6 times as long as basis, propodus 1.2 times as long as wide, dactylus 1.8 times as long as propodus. Pereopod 7 basis 1.1 times as long as greatest width; ischium 0.6 times as long as basis, with slight bulbous protrusion; merus proximal margin with large bulbous protrusion, merus 0.3 times as long as ischium, 0.4 times as long as wide; carpus 0.3 times as long as ischium, with slight bulbous protrusion, 0.8 times as long as wide; propodus 0.5 times as long as ischium, 1.7 times as long as wide; dactylus slender, 1.7 times as long as propodus, 3.0 times as long as basal width.

Pleopods without setae, exopod larger than endopod. Peduncle 1.1 times longer than rami, uropod peduncle lateral margin without setae; rami not extending beyond pleotelson, apices narrowly rounded. Endopod apically shallowly bifid, 3.7 times as long as greatest width, lateral margin straight, mesial margin concave. Exopod not extending to end of endopod, 3.4 times as long as greatest width, apically not bifid, lateral margin straight, terminating with no setae, mesial margin straight.

Male. Males were not present in the specimen lots. Trilles (1972a) noted that the mancae of Ceratothoa oxyrrhynchaena (which were originally labelled as second stage Ceratothoa oestroides ) had long antennae and the males possessed an appendix masculina.

Colour. Orange brown.

Size. Present material: adult females: 14–25 mm. Other records indicate ovigerous female: 10–48 mm; males: 3–19 mm; second stage pullus: 2.4 mm; first pullus: 2.4 mm ( Capapé & Pantoustier 1976; Montalenti 1948; Rokicki 1984b; Schioedte & Meinert 1883; Trilles 1972a; 1977; Yamauchi & Nunomura 2010).

Hosts. Dentex spariformis Ogilby, 1910 is the only recorded host in Australian waters; also recorded from Boops boops (Linnaeus, 1758) (see Euzet & Trilles 1961; Ramdane & Trilles 2008), roof of mouth in Spicara maena (Linnaeus, 1758) (see Quintard-Dorques 1966), on Maenidae fish (see Trilles & Raibaut 1971), stomach of Zeus faber Linnaeus, 1758 (see Trilles 1972b), pharyngeal cavity, gill slit and cloaca on Raja asterias Delaroche, 1809 , pharyngeal cavity of Scyliorhinus stellaris (Linnaeus, 1758) , gill slit on Raja clavata Linnaeus, 1758 pharyngeal cavity and gills of Torpedo marmorata Risso, 1810 (see Capapé & Pantoustier 1976), fish from families Maeidae, Sparidae and Rajidae ( Rokicki 1985) , from the buccal cavity of Spicara smaris (Linnaeus, 1758) (see Ramdane et al. 2007; Ramdane & Trilles 2008); Doederleinia berycoides Hilgendorf, 1879 (see Yamauchi 2009; Yamauchi & Nunomura 2010).

Distribution. Australia: off Mackay and Swains Reef, Queensland. Also western Pacific Ocean to the northeastern Atlantic and Mediterranean regions: Japan ( Koelbel 1878; Nierstrasz 1915; Nunomura 2006; Saito et al. 2000; Schioedte & Meinert 1883; Tatsu 2002; Thielemann 1910; Yamauchi 2009; Yamauchi & Nunomura 2010), Italy ( Montalenti 1948), France ( Euzet & Trilles 1961; Quintard-Dorques 1966), Tunisia ( Capapé & Pantoustier 1976; Trilles & Raibaut 1971), Algeria ( Ramdane et al. 2007; Ramdane & Trilles 2008; Trilles 1972b), Mauritania, and Gulf of Suez ( Trilles 1972b), Croatia ( Trilles 1977; Trilles et al. 1989).

Remarks. The Australian specimen is redescribed as it is the first occurrence of the species in Australia and this record is distant to all other records, which are primarily northwestern Pacific, North Atlantic and Mediterranean, and to highlight similarities and differences between Ceratothoa oxyrrhynchaena and Ceratothoa collaris ( Schioedte and Meinert, 1883) as existing descriptions were insufficient to discriminate between these two species.

Koelbel (1878) described Ceratothoa oxyrrhynchaena from Japan with few illustrations from an unidentified host. Ceratothoa oxyrrhynchaena has a stout body, very wide carina on the basis of pereopod 7, large pereonite 1 with acute anterolateral projections, uropods shorter than the pleotelson length, and males have an appendix masculina. The Australian specimen of Ceratothoa oxyrrhynchaena agrees with Koelbel’s (1878) illustration of the holotype, and also the recent descriptions and figures given by Horton (2000) and Yamauchi (2009), all of these accounts being consistent with each other.

Ceratothoa collaris and Ceratothoa oestroides Dana, 1852 are the most similar species to Ceratothoa oxyrrhynchaena . Ceratothoa collaris has similarly prominent anterolateral projections that do not extend past the eyes, a wide pleotelson (same width or wider than pleon), uropods which do not extend past the pleotelson and the pereopod 7 merus with a large bulbous protrusion, but differs from Ceratothoa oxyrrhynchaena in the following: dorsal surface slightly nodular, body elongate (2.5 vs 2.2 as long as wide), pleotelson posterior margin irregular, and males lack an appendix masculina. According to Yamauchi (2009), Ceratothoa collaris can be distinguished from Ceratothoa oxyrrhynchaena by the indented outer margin of the antenna.

Yamauchi (2009) concluded that the records of Iwasa (1947) and Shiino (1965) are a misidentification according to the following aspects: pereonite 1 anterolateral margins are bluntly produced; pleon is weakly immersed in pereonite 7 and the uropod rami are subequal in length and very short, an opinion with which we agree.

Yamaguti (1938) recorded Ceratothoa oxyrrhynchaena (as Meinertia oxyrrhynchaena ) from the mouth of the red seabream Pagrus major (Temminck & Schlegel, 1843) (as Pagrosomus unicolor ) from the Inland Sea, Japan. This record is a misidentification as the only species known to inhabit the mouth cavity of Pagrus major in Japanese waters was actually a different species (Yamauchi, unpublished data). Yamauchi (2009) considers records of Ceratothoa oxyrrhynchaena from Bruce (1982), Yu and Li (2003b) to be incorrect according to the following features: anterior margin of cephalon not produced; pereopod 7 basis without a well-developed carina; pereopod 7 merus without an anterior expansion.

The holotype is deposited at the Naturehistorisches Museum, Vienna (NMHW 6216) ( Horton 2000).

Figures

FIGURE 4. Ceratothoa oxyrrhynchaena, ovigerous female (20 mm) (MTQ W 15730). A, dorsal view; B, dorsal view of pereonite 1 and cephalon; C, dorsal view of pleotelson; D, lateral view.

FIGURE 5. Ceratothoa oxyrrhynchaena, ovigerous female (20 mm) (MTQ W 15730). A, antennule; B, antenna; C, maxillule; D, maxillule tip; E, mandible; F, maxilla; G, maxillab tip; H, maxilliped; I, maxilliped article 3; J, uropod.

FIGURE 6. Ceratothoa oxyrrhynchaena, ovigerous female (20 mm) (MTQ W 15730). A – D, pereopod 1, 2, 6, 7 respectively; E – I, pleopod 1 – 5 respectively.