Biological Invasions of Cold-Water Coastal Ecosystems - Aquatic ...

Chapt 9C4. Peracaridan Crustaceans, page 9C4- 8
Paramoera bousfieldi* 2
Paramoera mohri* 1
Parampithoe humeralis.* 2
Parampithoe mea* 1
Photis brevis 2
Pontogeneia inermis 3
Pontogeneia ivanovi* 1
Pontoporeia femorata* 2
Spinulogammarus subcarinatus* 1
Trasorchestia traskiana 3
Caprellidea
Caprella alaskana* 1
Caprella gracilior* 1
Caprella irregularis* 2
Metacaprella kennerlyi* 2
Total Species 38 14 54
Records/Species 1.4 2.1 1.8
The diversity of species collected is nearly nearly constant among sites (66 to 60 and 59,
respectively, between San Francisco, Puget Sound and Prince William Sound). Of the 54 native
species collected in Alaska, 52 (96%) were collected also in San Francisco Bay or Puget Sound
(Table 9C4.1). The common pool of native species and the similar species diversities collected
among the three areas both indicate that the habitat selection, collection and sample processing
methods of the rapid assessment surveys were consistent among the three areas. Little variation
in NIS diversity among these three sample sets was therefore likely to result from sample biases.
From San Francisco Bay north to Puget Sound and Prince William Sound, introduced
peracaridan species declined from 38 to 15 to 0 (Figure 9C4.3, X 2 > 27.01; p < 0.0001; df = 2),
while the frequencies of cryptogenic peracaridan species were nearly constant at 11, 10 and 8,
respectively (X 2 = 2.0; p > 0.73; df = 2). In contrast, the frequencies of native species increased
to the north from 17 to 35 and 52 (Figure 9C4.3, X 2 > 27.01; p < 0.0001; df = 2 ). All
peracaridan NIS and all but two of the cryptogenic peracaridan species at any site also occurred
in San Francisco Bay while only 17 of the 54 native species were recovered from San Francisco
Bay (Table 9C4.1, Figure 9C4.3). The peracaridan NIS that managed to invade northeast Pacific
estuaries thus have adaptations to lower latitude climates than do the native species. The
affinities of peracaridan NIS for low latitude climates closely corresponds to a pattern that would
be expected if the peracaridan NIS are poorly adapted to cold water conditions or other factors of
climate that vary with latitude.