Kane et al : Prevalence of Xenobalanus globicipitis on cetacean species In the eastern tropical Pacific Ocean 
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Table 2 
Dates and geographic locations (latitude and longitude) for sightings of newly documented cetacean hosts of Xenobalanus in the 
eastern tropical Pacific Ocean in 2003. Data are the following: total number of individuals of the species photographed (“individ- 
uals”), total number of these individuals observed with barnacles (“infested individuals”), and barnacle intensity and anatomical 
location on the host (“intensity and location on the host”). 
Host 
Individuals 
Infested 
individuals 
Intensity and 
location on the host 
Date 
Geographic location 
Balaenoptera edeni 
Bryde’s whale 
64 
3 
4 on dorsal fin 
03 November 2003 
09.012°S 079.302°W 
Delphinus capensis 
long-beaked 
common dolphin 
69 
1 
1 on right pectoral 
flipper 
12 August 2003 
25.620°N 109.456°W 
Megaptera novaeangliae 
humpback whale 
34 
1 
1 on dorsal fin 
05 November 2003 
06.414°S 081.176°W 
Stenella longirostris 
orientalis 
eastern spinner dolphin 
99 
1 
1 on left pectoral 
flipper 
15 August 2003 
21.448°N 108.084°W 
Stenella longirostris hybrid 
whitebelly spinner 
dolphin 
91 
1 
1 on dorsal fin 
20 August 2003 
08.857°N 145.098°W 
Stenella longirostris 
southwestern 
southwestern 
spinner dolphin 
32 
1 
2 or more on right 
pectoral flipper 
14 October 2003 
05.084°S 097.974°W 
sented the majority of individuals used in the analysis 
(14%), whereas blue whales (1%) and fin whales (0.2%) 
were rarely encountered. The number of barnacles was, 
therefore, independent of number of individuals observed 
(R 2 = 0.00, F=0.10, P=0.08). 
Xenobalanus was found in coastal as well as offshore 
waters of the ETP (Fig. 1). All 22 species were repre- 
sented in offshore sightings and 28% of individuals 
encountered were seen in waters greater than 600 km 
from land, and at a maximum distance of 4287 km 
from land. Of these offshore occurrences, 39 Xenobala- 
nus were observed on 18 individuals comprising seven 
species. Xenobalanus was primarily observed in three 
areas: 1) waters around the Baja California peninsula, 
2) the Costa Rica Dome and waters extending west 
along the 10°N Thermocline Ridge, and 3) waters off 
Peru and the Galapagos Archipelago. All three areas 
are known as areas of increased primary productivity 
within the ETP (Fig. 1, Fiedler et al., 1991; Pennington 
et al., 2006). 
For killer whales, which were examined in more de- 
tail, of the 68 whales infested with 130 barnacles, the 
mean intensity of infestation was 1.9 barnacles per 
whale. The greatest numbers of killer whales were pho- 
tographed in 1998-2003, and these whales also had the 
greatest intensity of barnacles. This observed increase 
in intensity was most likely the result of improved pho- 
tographic techniques. The observed numbers of killer 
whales with 0, 1, 2, 3, and >3 barnacles were 286, 38, 
15, 7, and 8, respectively. This is significantly different 
from the expected 245, 90, 17, 2, and 0 infested whales, 
respectively, as predicted by a Poisson distribution with 
mean 130/354 = 0.367 (%|>300, PcO.00001). The vari- 
ance (0.941) was much larger than the mean (0.367). 
Literature review 
A chart of the worldwide distribution of Xenobalanus was 
generated from a review of the literature documenting 
regional occurrences of this genus (Fig. 2). Except for 
the ETP, Xenobalanus has been reported only within 
approximately 600 km from land, including the Faroe 
Islands and the Azores (sites 4 and 8). Figure 2 also 
demonstrates that Xenobalanus is highly cosmopolitan 
and has been reported in all oceans, namely in tropical, 
temperate, and polar waters. 
The literature review updates a previous review 
conducted by Rajaguru and Shantha (1992). Eighteen 
peer-reviewed accounts have been published since that 
review, including that of the present study (Table 3). 
Additionally, ten records of Xenobalanus had not been 
included in Rajaguru and Shantha’s (1992) review. An 
additional 14 cetacean species are now included: minke 
whale {Balaenoptera acutorostrata), Bryde’s whale, long- 
beaked common dolphin, Pacific white-sided dolphin, 
dusky dolphin (Lagenorhynchus obscurus ), right whale 
dolphin (Lissodelphis borealis), humpback whale, va- 
quita ( Phocoena sinus), Burmeister’s porpoise ( Pho - 
coena spinipinnis), franciscana (Pontoporia blainvillei), 
clymene dolphin ( Stenella clymene), spinner dolphin, 
