LIFE HISTORY AND ECOLOGY OF FRANCISCANA, PONTOPORIA BLAINVILLEI (CETACEA, PONTOPORIIDAE) - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 309

Franciscana is the final host of several gastrointestinal parasites. The frequency of
occurrence and infection levels of helminths varies according to the host's geographical
distribution (Andrade et al., 1997; Aznar et al., 1994, 1995; Marigo et al., 2002). Adult
acanthocephalans Corynosoma cetaceum (= Polymorphus arctocephali and P. cetaceum -
Aznar et al., 1999) typically found in the intestine of vertebrates, have been reported in the
pyloric stomach and, to a lesser degree, in the duodenal ampulla and the main stomach of
franciscana (Aznar et al., 2001). Franciscanas from southern São Paulo State showed very
low prevalence and intensity of this infection (Marigo et al., 2002) as do those from Rio
Grande do Sul State, Brazil, and Uruguay, while franciscanas from Argentina exhibit higher
infection levels (Andrade et al., 1997; Aznar et al., 1994; Brownell, 1975). Other
acanthocephalans, such as Corynosoma australe , commonly found free in the pyloric
stomach, and Bolbosoma turbinella, often firmly attached to the walls of the large intestine,
showed moderate to high prevalence with low abundance in franciscanas from Rio Grande do
Sul State (Andrade et al., 1997). The nematode Contracaecum sp. was found in the main
stomach, with a low prevalence, in dolphins from Argentina (Aznar et al., 1995), and
Uruguay (Brownell, 1975), while Anisakis typica was found in the stomachs of specimens
from Rio Grande do Sul State (Andrade et al., 1997) and Uruguay (Kagei et al., 1976), and A .
simplex in stomachs of franciscana from Argentina (Aznar et al., 2003). Although considered
rare, both the trematode Pholeter gastrophilus and the nematode Procamallanus sp. were
found in the stomachs of franciscanas from Argentina (Aznar et al., 1994) and Uruguay
(Kagei et al., 1976), respectively. The trematode Hadwenius pontoporiae , only known to
infect P. blainvillei , was found in the small intestine of specimens from São Paulo and Paraná
States (Marigo et al., 2002), Rio Grande do Sul State (Andrade et al., 1997), and Argentina
(Aznar et al., 1994; 1997; Raga et al., 1994). No parasites were found in the intestines of
individuals from Uruguay (Brownell, 1975), nor in the internal organs of franciscana from
northern Rio de Janeiro State, Brazil (Di Beneditto & Ramos, 2001; Santos et al., 1996). No
parasites were found in the lungs of specimens from São Paulo and Paraná States (Marigo et
al., 2002).
A GE AND G ROWTH
The franciscana's life span seems shorter than 20 years. The oldest aged franciscana was
a 21 year old female (Pinedo, 1991). The maximum observed age for males was 16 years
(Kasuya & Brownell, 1979). The age frequency distribution of incidentally caught and
washed ashore animals suggests that only a percentage of the population lives more than 12
years, regardless of their geographic location (Kasuya & Brownell, 1979; Pinedo, 1994;
Pinedo & Hohn, 2000; Di Beneditto & Ramos, 2001; Secchi et al., 2003b). Although this age-
at-death frequency distribution is negatively biased, the very small fraction of individuals
older than 12 years indicates that franciscana has one of the shortest life spans among all
cetaceans.
Mean asymptotic length for P. blainvillei from Rio de Janeiro State, Brazil, is 117.1 cm
for males ( n = 43) and 144.7 cm for females ( n = 43 - Ramos et al., 2000). For specimens
from São Paulo and Paraná states, Brazil, this measure is 113.3 cm for males ( n = 23) and
128.9 cm for females ( n = 18 - Barreto & Rosas, 2006). For individuals from Rio Grande do