Abstract

Based on published records and own data a summary is given of the geographical distribution of the currently known species of pentastomid parasites infecting crocodiles and alligators, as well as freshwater chelonians. A brief generic diagnosis is provided for each genus. Fourteen out of the currently 23 living crocodilian species have been recorded as being host to one or more pentastomes. Out of the 32 pentastome species six are considered species inquirendae. Presently, six genera of crocodilian pentastomes, Agema, Alofia, Leiperia, Sebekia, Selfia and Subtriquetra are recognized. African crocodiles harbour eight pentastome species, six of which have been recorded from the Nile crocodile, Crocodylus niloticus. Three species belong to the genus Sebekia, Alofia being represented by two and Leiperia by only one species. Two species, Alofia parva and Agema silvae-palustris, occur in the dwarf crocodile, Osteolaemus tetraspis, and the slender-snouted crocodile, Crocodylus cataphractus, exclusively, but a single Sebekia species is shared with the Nile crocodile. The genus Agema is endemic to the African region. Infective stages of the pentastome Subtriquetra rileyi, thought to utilize Nile crocodiles as final hosts, have been recovered only from fishes. The largest number of pentastome species is found in the Australasian region. Of these, the Indo-Pacific crocodile, Crocodylus porosus, harbours seven, representing the genera Alofia, Sebekia, Leiperia and Selfia. Selfia is exclusive to the latter host. The genus Subtriquetra has been reported from "Indian crocodiles", a term possibly referring to either Crocodylus palustris, Crocodylus porosus or Gavialis gangeticus. Ten species of pentastomes parasitizing the crocodilian genera Alligator, Caiman, Crocodylus and Melanosuchus have been recorded from the Neotropical region including the southern states of the North American continent. The two most wide-spread pentastome genera, Alofia and Sebekia, have been recorded together with representatives of the genus Subtriquetra and immature and larval forms of Leiperia. To date the two monospecific genera, Pelonia, from two terrapin species, Pelusios sinuatus and Pelomedusa subrufa, in South Africa, and Diesingia from Hydraspis geoffroyana and Hydromedusa tectifera in South America, are the only chelonian pentastomes recovered world-wide. A possible exception is the crocodilian pentastome Sebekia mississippiensis which can reach maturity in experimentally infected terrapins.

Highlights

  • The pentastomid parasites of chelonians and crocodilians are currently divided into the family Sebekidae and Subtriquetridae

  • Diesingia and Pelonia parasitize the lungs of chelonian final hosts (Junker & Boomker 2002; Junker, Riley & Boomker 2003)

  • A single member of Sebekia, Sebekia mississippiensis, might be able to reach maturity in chelonians, too, but as yet no mature specimens have been collected from naturally infected hosts (Dukes, Shealy & Rogers 1971)

Read more

Summary

INTRODUCTION

The pentastomid parasites of chelonians and crocodilians are currently divided into the family Sebekidae and Subtriquetridae. The former comprises seven genera, namely, Agema, Alofia, Selfia, Sebekia, Leiperia, Diesingia and Pelonia. Diesingia and Pelonia parasitize the lungs of chelonian final hosts (Junker & Boomker 2002; Junker, Riley & Boomker 2003). Members of the monogeneric family Subtriquetridae inhabit the nasopharynx of their crocodilian final hosts, but Subtriquetra rileyi, of which currently only infective larvae have been recovered, needs verification (Winch & Riley 1986a; Junker, Boomker & Booyse 1998). The second part of the check-list alphabetically lists the hosts and their synonyms, and, in alphabetical order, their respective parasites. GENERIC DIAGNOSIS: Overall shape typical of smaller members of the Sebekidae; males claviform, females with more uniform diameter and conical posterior terminating in a small blunt point; adult hooks smooth; blades smoothly curved without abrupt right-angled bend near to base; blade on anterior hook pair larger than that of posterior pair; fulcrum without cowl; mouth ovoid and sides of cadre united anteriorly and posteriorly by segments of chitin which appear as two crescents; copulatory spicules delicate and elongate; basal section without a hooked collar (Riley et al 1997)

Osteolaemus tetraspis
Crocodylus niloticus
AUSTRALASIAN REGION
Alligator mississippiensis
Unknown crocodilian
Crocodylus porosus
Hydromedusa tectifera
Leiperia australiensis Sebekia johnstoni Sebekia multiannulata
Sebekia novaeguineae
Pelonia africana
Diesingia megastoma
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call