Hexaglandula corynosoma ( Travassos, 1915 ) Petrochenko, 1958

Guillén-Hernández, Sergio, García-Varela, Martín & León, Gerardo Pérez-Ponce De, 2008, First record of Hexaglandula corynosoma (Travassos, 1915) Petrochenko, 1958 (Acanthocephala: Polymorphidae) in intermediate and definitive hosts in Mexico, Zootaxa 1873, pp. 61-68 : 63-65

Hexaglandula corynosoma ( Travassos, 1915) Petrochenko, 1958

Adult ( Figs. 1–2 )

Description: based on 10 males and 10 females. Presoma and anterior portion of trunk curved ventrally. Trunk elongated, swollen and tapering to blunt at posterior end. About same size in both sexes, 1.57–3.60 (2.35) mm long by 0.73–1.50 (0.460) mm wide. Trunk with spines extending posteriorly 250–720 (385) from junction with neck; genital spines absent. Proboscis cylindrical, 422–490 (458) long by 112–180 (146) wide, armed with 16 longitudinal rows of 11 hooks each. Neck conical, 250–412 (300) long; width at base of proboscis 100–130 (113), 287–400 (366) at junction with trunk. Proboscis receptacle double-walled, attached at base of proboscis, 390–800 (595) long, with cerebral ganglion at mid–level. Testes slightly ovoid, located in swollen portion of trunk, 237–320 (278) long by 242-315 (268) wide. Cement glands 6. Genital pore of females subterminal, ventral. Eggs 50–72 (63) long by 20–32 (27) wide.

Cystacanth ( Fig. 3 )

Description: based on 10 males and 10 females. Trunk shape similar to that of adult, 1.11–146 (1.27) long by 400–530 (450) wide, armed with spines extending 175–350 (247) from junction with neck to end of swollen region. Neck conical, 150–325 (232) long by 80–162 (117) wide at the level of junction with proboscis, 187–312 (241) wide at level of junction with trunk. Proboscis almost cylindrical, 380–450 (421) long by 100–180 (132) wide. Number of rows and number of hooks per row identical to those of adults. Doublewalled proboscis receptacle inserted at base of proboscis, extending through neck, 350–656 (523) long. Testes, 120–205 (146) long by 62–110 (85) wide, tandem, located at mid-trunk, posterior to swollen region.

Remarks: Recently, Nickol et al. (2002) reported for the first time the presence of cystacanths and adults of Hexaglandula corynosoma in the Southeastern U.S. and presented a detailed morphological description of both stages. The authors found cystacanths in the outside wall of the hindgut and in the hemocoel of fiddler crabs, Uca spinicarpa from Deer Island, Mississippi, and Uca rapax Smith, 1870 from Big Pine Key, Ohio Key, and Indian River Lagoon, Florida. They also found adults in N. violacea from Molasses Key, Florida. In general, morphological traits and measurements of body structures in our specimens closely resemble those described by Nickol et al. (2002).

Our work represents the first report of Hexaglandula corynosoma in Mexico. It was found in the same host species, both intermediate and definitive, as in the Southeastern U.S. The distribution of U. spinicarpa extends along intertidal shores of the Western Atlantic, from Northwest Florida southwards to the Yucatán peninsula in México ( Barnwell & Thurman, 1984). That of U. rapax is even wider; the intertidal shores from the Gulf of Mexico to South America ( Crane 1975). However, cystacanths of H. corynosoma had not been reported from this host in Mexico. The definitive host, N. violacea , exhibits a very wide distributional range that includes North and South America ( Howell & Webb 1995; Root 1998). This study extends the distributional range of H. corynosoma . Mexico represents an intermediate distribution point for H. corynosoma , as does from Puerto Rico ( Cable & Quick 1954), because it also has been reported from Nyctanassa violacea , Nycticorax sp., and Florida cerulea in Brazil ( Travassos 1915; 1926). In the present study, H. corynosoma also was found along the Pacific slope of México, in Nayarit, but it has not been reported from the Pacific Coast of South America.

Figures

FIGURE 1. Adult of Hexaglandula corynosoma from Nyctanassa violacea, Ría Lagartos, Yucatán. Scale bar = 0.1 mm

FIGURE 2. Scanning electron microscopy of adult forms of Hexaglandula corynosoma; A. Anterior end showing proboscis and trunk spines, B. Proboscis. Scale bars: A = 250 µm; B. = 100 µm.

FIGURE 3. Cystacanth of Hexaglandula corynosoma from Uca spinicarpa, Progreso lagoon system, Yucatán. Scale bar = 0.1 mm.