172
Active host attraction is present in numerous members of tribe Lampsilini
(Unionidae).
Within this tribe some species (e.g. Lampsilis spp.) attract the host with mantle
lures that resemble hosts’ prey. After the fish touches (attacks) the mantle, the mussel releases the glochidia (Haag et al. 1999; Haag and Warren 2000; Bauer 2001b;
Zanatta and Murphy 2006; Barnhart et al. 2008). Female Epioblasma trap the head
of small fishes, which were attracted by the exposed mantle, by the quick closure of
the valves of their shell. While the fish is trapped, the mussel releases free glochidia
directly into its mouth, which enhances chances of infestation (Zanatta and Murphy
2006; Barnhart et al. 2008). However, fish often die as their head may be crushed,
so Barnhart et al. (2008) hypothesized that this strategy might aid in attracting other
fish using trapped fish as a lure.
5.4 Phylogeny of the Unionida
5.4.1 Origin of Unionida
Bivalves originated in the oceans not later than the Early Cambrian (Jell 1980; Cope
1996; Pojeta 2000; Parkhaev 2008; Elicki and Gürsu 2009; Bieler et al. 2013). Since
then they have invaded freshwaters multiple times (Gray 1988; Graf 2013). Bivalves
that are classified within the order Unionida have been present in freshwater habitats at least since the Late Triassic (Reeside 1927; Good 1998; Watters 2001; Graf
and Cummings 2006; Skawina and Dzik 2011; Van Damme et al. 2015), and presumably even earlier (Yates et al. 2012; Fig. 5.6). Unionoids are accepted as a
monophyletic lineage, which is supported by several characters including their
restriction to freshwater, brooding larvae in marsupia, and obligatory parasitic larvae of fish (with a few exceptions; Hoeh et al. 1998, 2001; Graf and Cummings
2006; Whelan et al. 2011). Members of the marine order Trigoniida, which is only
represented today by the relict Australian genus Neotrigonia, are considered to be
the closest relatives and the sistergroup of Unionida (Hoeh et al. 1998, 2001; Giribet
and Wheeler 2002; Graf and Cummings 2006; Combosch et al. 2017; Lopes-Lima
et al. 2017; Fig. 5.7). Newell and Boyd (1975) trace back the split between Unionida
and their closest relatives, the mostly brackish-water trigoniids classified in the family Pachycardiidae, to the Triassic.
5.4.2 Classification and Diversity
Members of the order Unionida are traditionally classified in six families: Unionidae
(674–753 species, and most widespread worldwide), Margaritiferidae (12–17 species, mostly Holarctic), Hyriidae (71–92 species, Neotropical and Australasian),
A. Skawina
Active host attraction is present in numerous members of tribe Lampsilini
(Unionidae).
Within this tribe some species (e.g. Lampsilis spp.) attract the host with mantle
lures that resemble hosts’ prey. After the fish touches (attacks) the mantle, the mussel releases the glochidia (Haag et al. 1999; Haag and Warren 2000; Bauer 2001b;
Zanatta and Murphy 2006; Barnhart et al. 2008). Female Epioblasma trap the head
of small fishes, which were attracted by the exposed mantle, by the quick closure of
the valves of their shell. While the fish is trapped, the mussel releases free glochidia
directly into its mouth, which enhances chances of infestation (Zanatta and Murphy
2006; Barnhart et al. 2008). However, fish often die as their head may be crushed,
so Barnhart et al. (2008) hypothesized that this strategy might aid in attracting other
fish using trapped fish as a lure.
5.4 Phylogeny of the Unionida
5.4.1 Origin of Unionida
Bivalves originated in the oceans not later than the Early Cambrian (Jell 1980; Cope
1996; Pojeta 2000; Parkhaev 2008; Elicki and Gürsu 2009; Bieler et al. 2013). Since
then they have invaded freshwaters multiple times (Gray 1988; Graf 2013). Bivalves
that are classified within the order Unionida have been present in freshwater habitats at least since the Late Triassic (Reeside 1927; Good 1998; Watters 2001; Graf
and Cummings 2006; Skawina and Dzik 2011; Van Damme et al. 2015), and presumably even earlier (Yates et al. 2012; Fig. 5.6). Unionoids are accepted as a
monophyletic lineage, which is supported by several characters including their
restriction to freshwater, brooding larvae in marsupia, and obligatory parasitic larvae of fish (with a few exceptions; Hoeh et al. 1998, 2001; Graf and Cummings
2006; Whelan et al. 2011). Members of the marine order Trigoniida, which is only
represented today by the relict Australian genus Neotrigonia, are considered to be
the closest relatives and the sistergroup of Unionida (Hoeh et al. 1998, 2001; Giribet
and Wheeler 2002; Graf and Cummings 2006; Combosch et al. 2017; Lopes-Lima
et al. 2017; Fig. 5.7). Newell and Boyd (1975) trace back the split between Unionida
and their closest relatives, the mostly brackish-water trigoniids classified in the family Pachycardiidae, to the Triassic.
5.4.2 Classification and Diversity
Members of the order Unionida are traditionally classified in six families: Unionidae
(674–753 species, and most widespread worldwide), Margaritiferidae (12–17 species, mostly Holarctic), Hyriidae (71–92 species, Neotropical and Australasian),
A. Skawina