Redescription of Monticellius indicum Mehra, 1939 (Digenea: Spirorchiidae) from the Heart of Green Sea Turtles (Chelonia mydas) in Costa Rica

Abstract

Monticellius indicum Mehra, 1939, is redescribed from the heart of green sea turtles (Chelonia mydas) at Tortuguero National Park, Caribbean coast of Costa Rica. Of the 40 green turtles examined, only 5 (12.5%) were infected with a mean intensity of 1.6. Our specimens are consistent with the original description based on a single fluke from the heart of the same host species in the Arabian Sea, Pakistan, but our redescription provides an unreported range of variation while adding new information about acetabulum structure and egg morphology.

Loggerhead turtle, Caretta caretta (Linnaeus, 1758) (Testudines, Cheloniidae), as a new host of Monticellius indicum Mehra, 1939 (Digenea: Spirorchiidae) and associated lesiond to spirorchiid eggs

“…The specimen analyzed had a thin body, with intestinal ceca not fused posteriorly and six irregularly-shaped testes located anterior to the ovary between the external seminal vesicle and the acetabulum; moreover, small spines were found on the acetabulum. These characteristics are in agreement with descriptions of the species using the identifi cation key proposed by Platt (2002) as well as all previous descriptions published on the species (Mehra, 1939;Santoro et al, 2009;. The morphometric analysis and comparison with previously published data on the parasite (Table 1) revealed that the specimen described herein has a larger width of the body, esophagus and ovary, larger length of the external seminal vesicle, larger width of the acetabulum and greater distances between the posterior region of the body and the acetabulum, anterior testicle, external seminal vesicle, ovary and vitelline reservoir.…”

“…Wolke et al (1982) described eggs from the genus Monticellius as type 1, with the following characteristics: "…yellow-brown, elongate and bore two processes, one of which was frequently hooked…" In the present study, only one egg was found in the uterus and exhibited one of the processes terminating in an oval structure (Fig. 1B), which is the same structure described previously by Santoro et al (2009), but not by Mehra (1939), who described M. indicum eggs as "large with narrow, somewhat curved or hook-shaped prolongations at both ends". Considering the redescription performed by Santoro et al (2009) and the present report, we believe that this characteristic could be used in the differential diagnosis of M. indicum eggs.…”

“…Unfortunately, little is known about this species, as only 11 specimens have been studied morphologically (Mehar, 1939;Santoro et al 2006Santoro et al , 2009Werneck & Silva, 2015;. To date, only four papers detailed on morphological features of M. indicum on the basis of specimens collected in green turtles from Pakistan (Mehra, 1939), Brazil and Costa Rica (Santoro et al, 2009) as well as a hawksbill turtle, Eretmochelys imbricata (Linnaeus, 1766), in Brazil . The loggerhead turtle, Caretta caretta (Linnaeus, 1758), is a known host for members of Spirorchiidae represented by the genera Carettacola, Hapalotrema, Neospirorchis, Neocaballerotrema, and Shobanatrema shobanae however the last two are considered genera inquirenta (Smith, 1997).…”

“…Type 3 eggs are characterized as being round and without tapering and are characteristic of the genus Neospirorchis (Wolke et al, 1982). For parasite identifi cation, the taxonomic key for genera proposed by Platt (2002), the original description (Mehra, 1939), the redescription by Santoro et al (2009) and comments by were used for both morphological ( Fig. 1) and morphometric comparisons (Table 1).…”

“…To date, only 11 specimens of M. indicum have been described in the literature, 10 of which were found in C. mydas in Pakistan, Brazil and Costa Rica (Mehar, 1939;Santoro et al, 2006Santoro et al, , 2009Werneck & Silva 2015) and one was found in E. imbricata in Brazil . Thus, the present report represents the twelfth specimen described and the fi rst found in C. caretta.…”