Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992)

Suárez-Morales, Eduardo, Morales-Vela, Benjamín, Padilla-Saldívar, Janneth & Silva-Briano, Marcelo, 2010, The copepod Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992) (Harpacticoida), an epibiont of the Caribbean manatee, Journal of Natural History 44 (13 - 14), pp. 847-859: 848-853

publication ID 10.1080/00222931003615711

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scientific name

Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992)


Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992)  

( Figures 2–4 View Figure 2 View Figure 3 View Figure 4 )

Material examined

Five adult females, three adult males from a male T. manatus manatus   (BCH 49) sampled by Marco Benítez and Janneth Padilla on 22 March 2007 from Chetumal Bay, Quintana Roo, Mexico (ECO-CHZ-05296)   . Three adult females, three adult males from a female T. manatus   (BCH 40) sampled 11 October 2006 from Chetumal Bay , Quintana Roo, Mexico (ECO-CHZ-05297)   . Two adult females, four adult males from a female T. manatus   (BCH 42) sampled 13 October 2006 from Chetumal Bay , Quintana Roo, Mexico (ECO-CHZ-05298)   . Two adult females, two adult males from a female T. manatus   (BCH 42), same locality, date and collectors, processed for SEM, specimens at the Universidad de Aguascalientes, Mexico   . Six adult females, three ovigerous females, three adult males from the olive ridley turtle Lepidochelys olivacea   , sampled on 2 August 2002 from unknown beach south of Chamela , Jalisco, Mexico (19°28′ N, 105°03′ W) GoogleMaps   , coll. A. Peña de Niz, specimens undissected (ECO- CHZ-03574). Two adult females, one adult male from L. olivacea   , same locality, date and collector, processed for SEM, specimens at the Universidad de Aguascalientes, Mexico GoogleMaps   .


Morphology. The general morphology of the specimens collected from the Caribbean manatee is as described by Ogawa et al. (1997) from Japanese specimens collected from sea turtles and by Suárez-Morales and Laso-Wasem (2009) from specimens collected in the Mexican Pacific. The average size of the female specimens from the Caribbean manatee (0.95 mm, range 0. 92–1.05 mm, n = 30) is slightly lower than the size reported by Ortíz et al. (1992) from the type locality (1.1 mm) from a manatee, Ogawa et al. (1997) from sea turtles in Japanese waters (1.24 mm, range 1.14–1.32 mm), and Suárez-Morales and Laso-Wasem (2009) from sea turtles of the Mexican Pacific (1.11 mm, range 1.03–1.14 mm). Males were also slightly smaller (average 1.01 mm, n = 10) than in the other groups ( Japan 1.14 mm, Cuba 1.2 mm, Mexican Pacific 1.18 mm) ( Ortíz et al. 1992; Ogawa et al. 1997; Suárez-Morales and Laso- Wasem 2009).We found no differences in the body proportions or appendages of both groups of specimens from Mexico after the SEM-based comparison of specimens collected from sea turtles (Mexican Pacific) and those obtained from the Caribbean manatee (Mexican Atlantic). This analysis included the main taxonomic characters of the species, such as the structure of the first leg distal endopodal and exopodal segments armed with three claws (see Figures 2D View Figure 2 , 3E View Figure 3 , 4B,D,E View Figure 4 ), the relatively short caudal rami in both sexes ( Figure 2C,F View Figure 2 ), the cuticular ornamentation of the thoracic somites ( Figures 3E View Figure 3 , 4A,C View Figure 4 ) and urosomal somites ( Figures 2C,F View Figure 2 , 4A View Figure 4 ) in both males and females, and the structure of the maxillipeds ( Figures 2B,D,E View Figure 2 , 3D View Figure 3 ) and the antennae ( Figures 2E View Figure 2 , 3A,B View Figure 3 ).

Manatee infestation with Balaenophilus   . Of 54 manatees examined, 14 (25.9%, six males, eight females) were infested by B. manatorum   ; of these, incidence was highest in young adult females (five individuals infested), followed by young adult males (four individuals). Copepods were also present on adult males and females, but not on juvenile individuals (see Table 1). Of the two localities in which manatees were examined, B. manatorum   was recorded only from individuals captured in Chetumal Bay.

Balaenophilus   as an epibiont. It is possible to observe patches of B. manatorum   while the manatee is in the water; they are visible as ochre-coloured areas with the shape of the skin folds and wrinkles ( Figure 5B View Figure 5 ). These patches are also conspicuous when the manatee skin starts to dry out, during the tagging process ( Figure 5A,C,D View Figure 5 ). Harpacticoids were found clustered forming a granulose, soft mass loosely adhered to the skin of the manatee. The patches were of different sizes and densities, but were always associated with and longitudinally arranged along skin folds. Copepods were found directly attached to the skin, probably clinging to the smaller crevices and ridges of the irregular skin surface. All patches of B. manatorum   were related to body areas of the manatee with long, relatively deep skin folds, including the area around the muzzle ( Figure 5A View Figure 5 ), the bases of pectoral fins ( Figure 5B,C View Figure 5 ), the area around the nipples ( Figure 5D View Figure 5 ) and the base of the caudal fin, but not in the relatively exposed body depressions. Clusters of B. manatorum   were not observed around the anus or the genitalia ( Figure 6 View Figure 6 ). When the patches were removed from the skin, there was no visible effect of the presence of the colonies of B. manatorum   on the manatee. Clusters of this copepod were not related to groups of barnacles or algal patches.