Asymmetrione clibanarii Markham, 1975

Nascimento, Ana Caroliny M., Lima, Daniel, Yamada, Priscilla O. F., Yamada, Fábio H., Pinheiro, Allysson P. & Nascimento, Whandenson M., 2025, Expanding the geographic distribution and the first record from Brazil of Asymmetrione clibanarii Markham, 1975 (Isopoda: Bopyridae), an ectoparasite associated with hermit crabs of the genus Clibanarius Dana, 1852, Zootaxa 5661 (2), pp. 293-300 : 295

Asymmetrione clibanarii Markham, 1975

( Figs. 2 , 3 )

Stegias clibanarii . — Pearse, 1932: 4–5, figs. 22–26 (Dry Tortugas, Florida; infesting Clibanarius tricolor ).— Schultz, 1969: 323, fig. 515.

Asymmetrione clibanarii Markham, 1975: 260–263 , 264, 265, figs. 5–6 (original description).— Markham, 1978: 103, 115 (table 1).— Markham, 1986: 154,— Markham, 1988: 5–7, fig. 1, 56 (table 1).— Markham, 2003: 72 (mention).— Williams & Schuerlein, 2005: 101 (mention).— McDermott et al. 2010: 8 (table 1).— Romero-Rodriguez & Alvarez, 2023: 149 (table 2), 151, 156 (in key).

Asymmetrione no. 2, Bourdon, 1976 b: 366 (mention).

Material examined: Three ovigerous females (TL = 3.89 mm; 4.75 mm; 4.23mm) and three males (TL = 1.76 mm; 1.95 mm; 2.32 mm), Paraíso Beach, municipality of Cabo de Santo Agostinho (8°21’29.1”S 34°57’00.0”W), Pernambuco, Brazil, Pasinatto K., Nascimento W.M, Paixão P.H., coll, 24.X.2022; infesting the right branchial chamber of three individuals, two males and one female of C. antillensis (SL = 2.32 mm; 2.25 mm; 2.67 mm) (LACRUSE-0319) .

Geographical distribution: distributed along the Western Atlantic ( Fig. 1A ): Florida, USA and Bahamas, infesting Clibanarius tricolor (Gibbes, 1850) ( Markham 1975) ( Fig. 1B ); Colombia, infesting C. tricolor and C. antillensis ( Markham 1988) ( Fig. 1C ); Ascension Island, infesting Clibanarius sp. ( Markham 1978) ( Fig. 1D ); state of Pernambuco, Brazil, infesting C. antillensis (present study) ( Fig. 1E ).

Diagnosis: Female body with head strongly distorted to left side and deeply buried in first pereomere. Barbula present, featuring two projections on each side. Eyes present. Pereopods uniform in size. Pleon distinctly segmented. Oostegites unequal in size. Males exhibit head and thorax partially fused. Eyes located on lateral edges of head. Dorsal pigmentation visible across body. Pleon segmented. For more details, see Markham (1975).

Remarks: The specimens analyzed in the present study exhibit the same morphological characteristics as those described by Markham (1975) in the original description of A. clibanarii . Females ( Figs. 2A, B ): body features a rounded elevation, with the head distorted to the left side of the body and deeply embedded in the first pereomere. The barbula displays two lateral projections on each side resembling small teeth. Pereopods are of similar size, but with smaller posterior dactyli. The pleon comprises six unequal pleomeres. Males ( Fig. 2C ): the males analyzed are also morphologically consistent with the original description of A. clibanarii , showing an incompletely fused head and thorax. Eyes are present on the lateral edges of the head. All males examined exhibit a segmented pleon and dorsal pigmentation across the body. However, in male specimens of A. clibanarii from Paraíso Beach, the pigmentation consists of small, irregularly distributed black spots. In contrast, the allotype of A. clibanarii has small black dots ( Markham 1975), appearing less pigmented than the males evaluated in this study.

Figures

FIGURE 1. A. Map showing geographical distribution sites of the Asymmetrione clibanarii Markham, 1975; B. Occurrence of A. clibanarii in Florida, USA, and the Bahamas; C. Occurrence of A. clibanarii in Colombia; D. Occurrence of A. clibanarii in Ascension Island; E. New occurrence records of A. clibanarii in Pernambuco, Brazil.

FIGURE 2. Asymmetrione clibanarii Markham, 1975, female: A. habitus dorsal view, and B. habitus ventral view; male: C. habitus dorsal view. Scale bars: A, B = 1 mm; C = 0.5 mm.

FIGURE 3. Dorsal (A) and lateral (B) views of the host Clibanarius antillensis Stimpson, 1859, infested by the female (red arrows) and the male (green arrows) of Asymmetrione clibanarii Markham, 1975. Scale bar: A, B = 2 mm.