Parasitic copepods of the family Lernanthropidae Kabata, 1979 (Copepoda: Siphonostomatoida) from Australian fishes, with descriptions of seven new species Author Boxshall, Geoff A. Author Bernot, James P. Author Barton, Diane P. Author Diggles, Ben K. Author Q-Y, Russell Author Atkinson-Coyle, Toby Author Hutson, Kate S. text Zootaxa 2020 2020-02-17 4736 1 1 103 journal article 24025 10.11646/zootaxa.4736.1.1 c76ec731-0dc9-4fc4-8ea4-d90d90da9438 1175-5326 3669745 970D7D36-6D8C-4463-B9EA-D3B8E191BE72 Mitrapus oblongus ( Pillai, 1964 ) ( Fig. 39B , Fig. 42 ) Syn: Lernanthropus oblongus Pillai, 1964 Material examined: 15♀♀ and 5 ♂♂ (attached to ♀ ) from Herklotsichthys castelnaui (Ogilby, 1897) ( TC 17275), Moreton Bay, Queensland ; 19 January 2016 ; collected by G.A. Boxshall; QM Reg. No. W29502. 1♀ and and 1♂ from H. castelnaui ( TC 17229), Moreton Bay, Queensland ; 18 January 2016 ; collected by G.A. Boxshall; NHMUK Reg. No. 2018.296–297. 6♀♀ from H. castelnaui (as Harengula abbreviata ), Coffs Harbour, New South Wales ; 15 May 1981 ; collected by M. La Spina; NHMUK Reg. No. 2018.298–301. Differential diagnosis: Cephalothorax oval; anterolateral margins of cephalothorax folded downward to encircle base of antenna laterally. Trunk about 1.4 times longer than wide, covered with dorsal trunk plate extending posteriorly to overlap basal part of bilobed leg 4 ( Fig. 42 A–C); posterior margin of dorsal trunk plate entire and evenly convex. Anterior corners of trunk produced to form conspicuous, paired, knob-like protrusions. Lateral surfaces of trunk ornamented with numerous small papillae. Urosome comprising fifth pedigerous somite, genital complex and anal somite, all fused. Egg sacs linear. Caudal rami carried on ventral surface of abdomen; conical, tapering from broad base; about 1.5 times longer than width at base; armature comprising 2 large caudal setae located dorsally in proximal third, lateral seta located in mid-margin, plus 2 apical setae. Parabasal flagellum absent. Leg 2 biramous, with unimerous rami. Leg 3 bilobate with fleshy outer in inner lamellae; outer lamella orientated vertically, inner lobe shoehorn-like, partly fused along midline to other member of leg pair. Leg 4 bilobate; outer (exopodal) lobe elongate, inner (endopodal) lobe about half (42–52 %) of length of exopod; distal parts of both lobes protruding well beyond free posterior margin of dorsal trunk plate ( Fig. 42 A–C). Leg 5 absent. Body length of ♀ ranging from 1.87 to 2.13 mm , with a mean of 2.00 mm (based on 10 specimens ). Body length of figured male 0.91 mm ( Fig. 39B ). Distribution: This species was originally described (as Lernanthropus oblongus ) from India on the clupeid Sardinella fimbriata (Valenciennes, 1847) ( Pillai, 1964 ) . El-Rashidy & Boxshall (2009 ; 2010 ) recorded both sexes of M. oblongus from two clupeiform fishes caught in Mediterranean coastal waters off Alexandria ( Egypt ): the dussumieriid Etrumeus teres (DeKay, 1842) which is an established immigrant species from the Red Sea , and Sardinella aurita Valenciennes, 1847 , a native Mediterranean clupeid. Romero & Öktener (2010) subsequently reported M. oblongus from the latter host in Turkish coastal waters. This is the first record of the genus from Australian waters and the clupeid host Herklotsichthys castelnaui constitutes a new host record for M. oblongus . FIGURE 42 . Mitrapus oblongus ( Pillai, 1964 ) adult ♀. A, habitus, dorsal; B, habitus, lateral; C, habitus, ventral. Scale bar 1 mm. TABLE 4. Character states of females of Sagum species
Species Lateral head margins Caudal ramus shape Caudal ramus L:W ratio Dorsal caudal setae Leg 4 Visibility of leg 4 Data source
S. angulatum paired lobes short, cylindrical 1.2:1 unknown tapering concealed Krøyer, 1863
S. brotulae paired lobes tapering 2.8:1 proximal half flagellate tips visible Izawa, 2018
S. enneacentri paired lobes unknown unknown unknown flagellate tips visible Pillai, 1985
S. epinepheli large lobes tapering 2.8:1 proximal half flagellate tips visible Ho et al ., 2011
S. flagellatum paired lobes lobate “short” unknown flagellate tips tips visible Wilson, 1913
S. pillaisebastiani 3 angular lobes tapering 1.8:1 proximal half flagellate tips visible Pillai, 1985
S. posteli paired lobes leaf-like 1.0:1 unknown flagellate tips visible Toksen et al ., 2012
S. vespertilio large lobes leaf-like 2.5:1 proximal half flagellate tips tips visible Ho et al ., 2008
S. petersi weakly convex unknown unknown unknown flagellate tips visible Kabata, 1979a
S. bitaro linear leaf-like 2.1:1 distal half tapering concealed Uyeno & Naruse, 2018
S. caesionis linear leaf-like 1.5:1 unknown tapering tips visible Yamaguti, 1954
S. foliaceum linear tapering 2.5:1 unknown tapering visible Hewitt, 1968
S. folium linear leaf-like 1.8:1 distal half tapering concealed Ho et al ., 2011
S. gurukun linear leaf-like 1.4:1 proximal half tapering concealed Uyeno & Naruse, 2018
S. lativentris linear leaf-like 2.8:1 proximal half tapering tips visible present account
S. paracaesionis linear leaf-like 2.0:1 distal half tapering concealed Izawa, 2014
S. sanguineus linear leaf-like 2.7:1 proximal half tapering visible Song & Chen, 1976 ; present account
S. vietnamensis linear elongate, cylindrical 4.4:1 proximal half tapering concealed Kazachenko et al ., 2017
Remarks: Pillai (1985) commented that M. oblongus closely resembled M. rubiginosus ( Redkar, Rangnekar & Murti, 1949 ) (as L . rubiginosus ) collected from the clupeid Nematalosa nasus (Bloch, 1795) (as Chatoessus nasus ), but M. rubiginosus was subsequently recognised as a junior subjective synonym of M. heteropodus ( Yü, 1933 ) by El-Rashidy & Boxshall (2010) . Both sexes of M. oblongus were redescribed in detail by El-Rashidy & Boxshall (2010) .