Mate choice and reproductive conflict in simultaneous hermaphrodites

Animal Behaviour: Evolution and Mechanisms

Volumn , Issue , 2010, Pages 329-357

  Anthes, Nils ^a  

^a UNIVERSITY OF TÜBINGEN   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 84900878315     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1007/978-3-642-02624-9_12     Document Type: Chapter

References (143)

1. Angeloni L (2003) Sexual selection in a simultaneous hermaphrodite with hypodermic insemination: body size, allocation to sexual roles and paternity. Anim Behav 66:417-426
2. Angeloni L, Bradbury JW (1999) Body size influences mating strategies in a simultaneously hermaphroditic sea slug, Aplysia vaccaria. Ethol Ecol Evol 11:187-195
3. Angeloni L, Bradbury JW, Charnov EL (2002) Body size and sex allocation in simultaneously hermaphroditic animals. Behav Ecol 13:419-426
4. Angeloni L, Bradbury JW, Burton RS (2003) Multiple mating, paternity, and body size in a simultaneous hermaphrodite, Aplysia californica. Behav Ecol 14:554-560
5. Anthes N, Michiels NK (2005) Do 'sperm trading' simultaneous hermaphrodites always trade sperm? Behav Ecol 16:188-195
6. Anthes N, Michiels NK (2007) Precopulatory stabbing, hypodermic injections and unilateral matings in a hermaphroditic sea slug. Biol Lett 3:121-124
7. Anthes N, Putz A, Michiels NK (2005) Gender trading in a hermaphrodite. Curr Biol 15:R792-R793
8. Anthes N, Putz A, Michiels NK (2006a) Hermaphrodite sex role preferences: the role of partner body size, mating history and female fitness in the sea slug Chelidonura sandrana. Behav Ecol Sociobiol 60:359-367
9. Anthes N, Putz A, Michiels NK (2006b) Sex role preferences, gender conflict and sperm trading in simultaneous hermaphrodites: a new framework. Anim Be-hav 72:1-12
10. Arnqvist G, Nilsson T (2000) The evolution of polyandry: multiple mating and female fitness in insects. Anim Behav 60:145-164
11. Arnqvist G, Rowe L (2005) Sexual Conflict. Princeton University Press, Princeton
12. Axelrod R, Hamilton WD (1981) The evolution of cooperation. Science 211:1390-1396
13. Baminger H, Locher R, Baur B (2000) Incidence of dart shooting, sperm delivery, and sperm storage in natural populations of the simultaneously hermaphroditic land snail Arianta arbustorum. Can J Zool 78:1767-1774
14. Baur B (1992) Random mating by size in the simultaneously hermaphroditic land snail Arianta arbustorum: experiments and an explanation. Anim Behav 43:511-518
15. Baur B (1994) Multiple paternity and individual variation in sperm precedence in the simultaneously hermaphroditic land snail Arianta arbustorum. Behav Ecol Sociobiol 35:413-421
16. Baur B (1998) Sperm competition in molluscs. In: Birkhead TR, Møller AP (eds) Sperm Competition and Sexual Selection. Academic Press, London, pp 255-305
17. Baur B (2007) Reproductive biology and mating conflict in the simultaneously hermaphroditic land snail Arianta arbustorum. Am Malacol Bull 23:157-172
18. Baur B, Baur A (1997) Random mating with respect to relatedness in the simultaneously hermaphroditic land snail Arianta arbustorum. Invert Biol 116:294-298
19. Baur B, Locher R, Baur A (1998) Sperm allocation in the simultaneously hermaphroditic land snail Arianta arbustorum. Anim Behav 56:839-845
20. Bedhomme S, Bernasconi G, Koene JM, Lankinen A, Arathi HS, Michiels NK, Anthes N (2009) How does breeding system variation modulate sexual antagonism? Biol Lett 5:717-720
21. Berglund A, Rosenqvist G (2003) Sex role reversal in pipefish. Adv Stud Behav 32:131-167
22. Bojat NC, Haase M (2002) Sperm storage in the simultaneously hermaphroditic land snail Arianta arbustorum. J Zool Lond 258:497-503
23. Cadet C, Metz JAJ, Klinkhamer PGL (2004) Size and the not-so-single sex: disentangling the effects of size and budget on sex allocation in hermaphrodites. Am Nat 164:779-792
24. Chaine A, Angeloni L (2005) Size-dependent mating and gender choice in a simultaneous hermaphrodite, Bulla gouldiana. Behav Ecol Sociobiol 59:58-68
25. Chapman T, Liddle LF, Kalb JM, Wolfner MF, Partridge L (1995) Cost of mating in Drosophila melanogaster females is mediated by male accessory gland products. Nature 373:241-244
26. Charlesworth D, Charlesworth B (1987) Inbreeding depression and its evolutionary consequences. Annu Rev Ecol Syst 18:237-268
27. Charnov EL (1979) Simultaneous hermaphroditism and sexual selection. Proc Natl Acad Sci USA 76:2480-2484
28. Charnov EL (1982) The Theory of Sex Allocation. Princeton University Press, Princeton
29. Charnov EL, Bull JJ, Maynard-Smith J (1976) Why be an hermaphrodite? Nature 263:125-126
30. Chase R, Blanchard KC (2006) The snail's love-dart delivers mucus to increase paternity. Proc R Soc Lond B 273:1471-1475
31. Chase R, Vaga K (2006) Independence, not conflict, characterizes dart-shooting and sperm exchange in a hermaphroditic snail. Behav Ecol Sociobiol 59:732-739
32. Chen X, Baur B (1993) The effect of multiple mating on female reproductive success in the simultaneously hermaphroditic land snail Arianta arbustorum. Can J Zool 71:2431-2436
33. Crespi BJ (1989) Causes of assortative mating in arthropods. Anim Behav 38:980-1000
34. Crowley PH, Hart MK (2007) Evolutionary stability of egg trading and parceling in simultaneous hermaphrodites: the chalk bass revisited. J Theor Biol 246:420-429
35. Crozier WJ (1917) Evidence of assortive mating in a nudibranch. Proc Natl Acad Sci USA 3:519-522
36. Darwin C (1871) The Descent of Man and Selection in Relation to Sex. John Mu-ray, London
37. DeWitt TJ (1996) Gender contests in a simultaneous hermaphrodite snail: a size-advantage model for behaviour. Anim Behav 51:345-351
38. Dillen L, Jordaens K, Dieleman W, Backeljau T (2008) Effects of isolation and body size on the mating behaviour of the hermaphroditic land snail Succinea putris. Anim Behav 75:1401-1411
39. Eppley SM, Jesson LK (2008) Moving to mate: the evolution of separate and combined sexes in multicellular organisms. J Evol Biol 21:727-736
40. Escobar JS, Epinat G, Sarda V, David P (2007) No correlation between inbreeding depression and delayed selfing in the freshwater snail Physa acuta. Evolution 61:2655-2670
41. Evanno G, Madec L, Arnaud J-F (2005) Multiple paternity and postcopulatory sexual selection in a hermaphrodite: what influences sperm precedence in the garden snail Helix aspersa? Mol Ecol 14:805-812
42. Facon B, Ravigné V, Goudet J (2006) Experimental evidence of inbreeding avoidance in the hermaphroditic snail Physa acuta. Evol Ecol 20:395-406
43. Facon B, Ravigné V, Sauteur L, Goudet J (2007) Effect of mating history on gender preference in the hermaphroditic snail Physa acuta. Anim Behav 74:1455-1461
44. Facon B, Ravigné V, Goudet J (2008) Gender-role alternation in the simultaneously hermaphroditic freshwater snail Physa acuta: not with the same partner. Behav Ecol Sociobiol 62:713-720
45. Field SG, Michiels NK (2005) Parasitism and growth in the earthworm Lumbricus terrestris: fitness costs of the gregarine parasite Monocystis sp. Parasitology 130:397-403
46. Field SG, Schirp HJ, Michiels NK (2003) The influence of Monocystis sp infection on growth and mating behaviour of the earthworm Lumbricus terrestris. Can J Zool 81:1161-1167
47. Fischer EA (1984) Egg trading in the chalk bass, Serranus tortugarum, a simultaneous hermaphrodite. Z Tierpsychol 66:143-151
48. Fricke C, Wigby S, Hobbs R, Chapman T (2009) The benefits of male ejaculate sex peptide transfer in Drosophila melanogaster. J Evol Biol 22:275-286
49. Gascoigne T (1993) Stylets, styles and other cuticular extensions of the male duct in the order Sacoglossa (Gastropoda). Boll Malacol 29:139-146
50. Ghiselin MT (1969) The evolution of hermaphroditism among animals. Q Rev Biol 44:189-208
51. Grove AJ (1925) On the reproductive processes of the earthworm, Lumbricus ter-restris. Q J Microsc Sci 69:245-290
52. Haase M, Karlsson A (2004) Mate choice in a hermaphrodite: you won't score with a spermatophore. Anim Behav 67:287-291
53. Iyer P, Roughgarden J (2008) Dioecy as a specialization promoting sperm delivery. Evol Ecol Res 10:867-892
54. Janicke T, Schärer L (2009) Determinants of mating and sperm-transfer success in a simultaneous hermaphrodite. J Evol Biol 22:405-415
55. Jarne P, Auld JR (2006) Animals mix it up too: the distribution of self-fertilization among hermaphroditic animals. Evolution 60:1816-1824
56. Jarne P, Charlesworth D (1993) The evolution of the selfing rate in functionally hermaphrodite plants and animals. Ann Rev Ecol Syst 24:441-466
57. Jarne P, Perdieu M-A, Pernot A-F, Delay B, David P (2000) The influence of self-fertilization and grouping on fitness attributes in the freshwater snail Physa acuta: population and individual inbreeding depression. J Evol Biol 13:645-655
58. Johnstone RA, Keller L (2000) How males can gain by harming their mates: sexual conflict, seminal toxins, and the cost of mating. Am Nat 156:368-377
59. Jordaens K, Pinceel J, Backeljau T (2005) Mate choice in the hermaphroditic land snail Succinea putris (Stylommatophora: Succineidae). Anim Behav 70:329-337
60. Jordaens K, Dillen L, Backeljau T (2007) Effects of mating, breeding system and parasites on reproduction in hermaphrodites: pulmonate gastropods (Mol-lusca). Anim Biol 57:137-195
61. Klinkhamer PGL, de Jong TJ, Metz H (1997) Sex and size in cosexual plants. Trends Ecol Evol 12:260-265
62. Koene JM (2005) Allohormones and sensory traps: a fundamental difference between hermaphrodites and gonochorists? Invert Reprod Dev 48:101-107
63. Koene JM, Chase R (1998a) Changes in the reproductive system of the snail Helix aspersa caused by mucus from the love dart. J Exp Biol 201:2313-2319
64. Koene JM, Chase R (1998b) The love dart of Helix aspersa Müller is not a gift of calcium. J Mollus Stud 64:75-80
65. Koene JM, Ter Maat A (2005) Sex role alternation in the simultaneous hermaphroditic pond snail Lymnaea stagnalis is determined by the availability of seminal fluid. Anim Behav 69:845-850
66. Koene JM, Ter Maat A (2007) Coolidge effect in pond snails: male motivation in a simultaneous hermaphrodite. BMC Evol Biol 7:212
67. Koene JM, Sundermann G, Michiels NK (2002) On the function of body piercing during copulation in earthworms. Invert Reprod Dev 41:35-40
68. Koene JM, Pförtner T, Michiels NK (2005) Piercing the partner's skin influences sperm uptake in the earthworm Lumbricus terrestris. Behav Ecol Sociobiol 59:243-249
69. Koene JM, Montagne-Wajer K, Ter Maat A (2007) Aspects of body size and mate choice in the simultaneously hermaphroditic pond snail Lymnaea stagnalis. Anim Biol 57:247-259
70. König S, Mehlich A-M, Bullesbach J, Michiels NK (2006) Allohormones in Lum-bricus terrestris? Mass spectrometry of the setal gland product indicates possible role of ubiquitin. Invert Reprod Dev 49:103-112
71. Kokko H, Jennions MD (2008) Parental investment, sexual selection and sex ratios. J Evol Biol 21:919-948
72. Kokko H, Ots I (2006) When not to avoid inbreeding. Evolution 60:467-475
73. Ladurner P, Schärer L, Salvenmoser W, Rieger RM (2005) A new model organism among the lower Bilateria and the use of digital microscopy in taxonomy of meiobenthic Platyhelminthes: Macrostomum lignano, n. sp. (Rhabdito-phora, Macrostomorpha). J Zool Syst Evol Res 43:114-126
74. Landolfa MA (2002) On the adaptive function of gamete trading in the black hamlet Hypoplectrus nigricans. Evol Ecol Res 4:1191-1199
75. Landolfa MA, Green DM, Chase R (2001) Dart shooting influences paternal reproductive success in the snail Helix aspersa. Behav Ecol 12:773-777
76. Leonard JL (1991) Sexual conflict and the mating systems of simultaneously hermaphroditic gastropods. Am Malacol Bull 9:45-58
77. Leonard JL (2006) Sexual selection: lessons from hermaphrodite mating systems. Integr Comp Biol 46:349-367
78. Leonard JL, Lukowiak K (1984) Male-female conflict in a simultaneous hermaphrodite resolved by sperm trading. Am Nat 124:282-286
79. Lessells CM (2006) The evolutionary outcome of sexual conflict. Philos Trans R Soc Lond B 361:301-317
80. Lüscher A, Milinski M (2003) Simultaneous hermaphrodites reproducing in pairs self-fertilize some of their eggs: an experimental test of predictions of mixed-mating and Hermaphrodite's Dilemma theory. J Evol Biol 16:1030-1037
81. Lüscher A, Wedekind C (2002) Size-dependent discrimination of mating partners in the simultaneous hermaphroditic cestode Schistocephalus solidus. Behav Ecol 13:254-259
82. Mank JE, Promislow DEL, Avise JC (2006) Evolution of alternative sex-determining mechanisms in teleost fishes. Biol J Linn Soc 87:83-93
83. McCarthy TM (2004) Effects of pair-type and isolation time on mating interactions of a freshwater snail, Physa gyrina (Say, 1821). Am Malacol Bull 19:47-55
84. McCarthy TM, Sih A (2008) Relatedness of mates influences mating behaviour and reproductive success of the hermaphroditic freshwater snail Physa gyrina. Evol Ecol Res 10:77-94
85. Michiels NK (1998) Mating conflicts and sperm competition in simultaneous hermaphrodites. In: Birkhead TR, Møller AP (eds) Sperm Competition and Sexual Selection. Academic Press, London, pp 219-254
86. Michiels NK, Bakovski B (2000) Sperm trading in a hermaphroditic flatworm: reluctant fathers and sexy mothers. Anim Behav 59:319-325
87. Michiels NK, Koene JM (2006) Sexual selection favours harmful mating in hermaphrodites more than in gonochorists. Integr Comp Biol 46:473-480
88. Michiels NK, Newman LJ (1998) Sex and violence in hermaphrodites. Nature 391:647
89. Michiels NK, Streng A (1998) Sperm exchange in a simultaneous hermaphrodite. Behav Ecol Sociobiol 42:171-178
90. Michiels NK, Hohner A, Vorndran IC (2001) Precopulatory mate assessment in relation to body size in the earthworm Lumbricus terrestris: avoidance of dangerous liaisons? Behav Ecol 12:612-618
91. Michiels NK, Raven-Yoo-Heufes A, Kleine Brockmann K (2003) Sperm trading and sex roles in the hermaphroditic opisthobranch sea slug Navanax inermis: eager females or opportunistic males? Biol J Linn Soc 78:105-116
92. Michiels NK, Crowley PH, Anthes N (2009) Accessory male investment can undermine the evolutionary stability of simultaneous hermaphroditism. Biol Lett 5:709-712
93. Monroy F, Aira M, Velando A, Domínguez J (2005) Size-assortative mating in the earthworm Eisenia fetida (Oligochaeta, Lumbricidae). J Ethol 23:69-70
94. Mulvey M, Vrijenhoek RC (1981) Multiple paternity in the hermaphroditic snail, Biomphalaria obstructa. J Hered 72:308-312
95. Munday PL, Buston PM, Warner RR (2006) Diversity and flexibility of sex-change strategies in animals. Trends Ecol Evol 21:89-95
96. Norton CG, Johnson AF, Mueller RL (2008) Relative size influences gender role in the freshwater hermaphroditic snail, Helisoma trivolvis. Behav Ecol 19:1122-1127
97. Ohbayashi-Hodoki K, Ishihama F, Shimada M (2004) Body size-dependent gender role in a simultaneous hermaphrodite freshwater snail, Physa acuta. Be-hav Ecol 15:976-981
98. Otsuka C, Rouger Y, Tobach E (1980) A possible relationship between size and reproductive behaviour in a population of Aplysia punctata (Cuvier, 1803). Veliger 23:159-163
99. Pal P, Erlandsson J, Sköld M (2006) Size-assortative mating and non-reciprocal copulation in a hermaphroditic intertidal limpet: test of the mate availability hypothesis. Mar Biol 148:1273-1282
100. Pennings SC (1991) Reproductive behavior of Aplysia californica Cooper: diel patterns, sexual roles and mating aggregations. J Exp Mar Biol Ecol 149:249-266
101. Peters A, Michiels NK (1996a) Do simultaneous hermaphrodites choose their mates? Effects of body size in a planarian flatworm. Freshwater Biol 36:623-630
102. Peters A, Michiels NK (1996b) Evidence for lack of inbreeding avoidance by selective mating in a simultaneous hermaphrodite. Invert Biol 115:99-103
103. Petersen CW (1995) Reproductive behavior, egg trading, and correlates of male mating success in the simultaneous hermaphrodite, Serranus tabacarius. En-vironm Biol Fishes 43:351-361
104. Petersen CW (2006) Sexual selection and reproductive success in hermaphroditic seabasses. Integr Comp Biol 46:439-448
105. Pongratz N, Michiels NK (2003) High multiple paternity and low last-male sperm precedence in a hermaphroditic planarian flatworm: consequences for reciprocity patterns. Mol Ecol 12:1425-1433
106. Preece T, Mao Y, Garrahan JP, Davison A (2009) Harmful mating tactics in hermaphrodites. Am Nat 173:632-639
107. Putz A, Michiels NK, Anthes N (2008) Mating behaviour of the sperm trading hermaphroditic sea slug Chelidonura hirundinina: repeated sex role alternation balances reciprocity. Ethology 114:85-94
108. Puurtinen M, Kaitala V (2002) Mate-search efficiency can determine the evolution of separate sexes and the stability of hermaphroditism in animals. Am Nat 160:645-660
109. Reise H, Visser S, Hutchinson JMC (2007) Mating behaviour in the terrestrial slug Deroceras gorgonium: is extreme morphology associated with extreme behaviour? Anim Biol 57:197-215
110. Ridley M (1983) The Explanation of Organic Diversity. Oxford University Press, Oxford
111. Rogers DW, Chase R (2001) Dart receipt promotes sperm storage in the garden snail Helix aspersa. Behav Ecol Sociobiol 50:122-127
112. Rowe L, Arnqvist G (1996) Analysis of the causal components of assortative mating in water striders. Behav Ecol Sociobiol 38:279-286
113. Schärer L (2009) Tests of sex allocation theory in simultaneously hermaphroditic animals. Evolution 63:1377-1405
114. Schärer L, Janicke T (2009) Sex allocation and sexual conflict in simultaneously hermaphroditic animals. Biol Lett 5:705-708
115. Schjørring S (2009) Sex allocation and mate choice of selfed and outcrossed Schistocephalus solidus (Cestoda). Behav Ecol 20:644-650
116. Schjørring S, Jäger I (2007) Incestuous mate preference by a simultaneous hermaphrodite with strong inbreeding depression. Evolution 61:423-430
117. Schmitt V, Anthes N, Michiels NK (2007) Mating behaviour in the sea slug Elysia timida (Opisthobranchia, Sacoglossa): hypodermic injection, sperm transfer and balanced reciprocity. Front Zool 4:17
118. Sella G (1985) Reciprocal egg trading and brood care in a hermaphroditic poly-chaete worm. Anim Behav 33:938-944
119. Sella G, Lorenzi MC (2000) Partner fidelity and egg reciprocation in the simultaneously hermaphroditic polychaete worm Ophryotrocha diadema. Behav Ecol 11:260-264
120. Sella G, Ramella L (1999) Sexual conflict and mating systems in the dorvilleid genus Ophryotrocha and the dinophilid genus Dinophilus. Hydrobiologia 402:203-213
121. Sella G, Premoli MC, Turri F (1997) Egg trading in the simultaneously hermaphroditic polychaete worm Ophryotrocha gracilis (Huth). Behav Ecol 8:83-86
122. Siva-Jothy MT (2006) Trauma, disease and collateral damage: conflict in cimi-cids. Philos Trans R Soc Lond B 361:269-275
123. Smolensky N, Romero MR, Krug PJ (2009) Evidence for costs of mating and self-fertilization in a simultaneous hermaphrodite with hypodermic insemination, the opisthobranch Alderia willowi. Biol Bull 216:188-199
124. Sprenger D, Anthes N, Michiels NK (2008a) Multiple mating affects offspring size in the opisthobranch Chelidonura sandrana. Mar Biol 153:891-897
125. Sprenger D, Faber J, Michiels NK, Anthes N (2008b) Natural female mating rate maximizes hatchling size in a marine invertebrate. J Anim Ecol 77:696-701
126. Sprenger D, Lange R, Michiels NK, Anthes N (2009) The role of body size in early mating behavior in a simultaneous hermaphrodite, Chelidonura san-drana. Behav Ecol Sociobiol 63:953-958
127. Sprenger D, Lange R, Michiels N, Anthes N (2010) Sources of phenotypic variance in egg and larval traits in a marine invertebrate. Evol Ecol, doi: 10.1007/s10682-10009-19300-x
128. Switzer-Dunlap M, Meyers-Schulte K, Gardner EA (1984) The effect of size, age, and recent egg laying on copulatory choice of the hermaphroditic mollusc Aplysia juliana. Int J Invert Repr Dev 7:217-225
129. Tian-Bi Y-NT, N'Goran EK, N'Guetta S-P, Matthys B, Sangare A, Jarne P (2008) Prior selfing and the selfing syndrome in animals: an experimental approach in the freshwater snail Biomphalaria pfeifferi. Gen Res 90:61-72
130. Tomiyama K (1996) Mate-choice criteria in a protandrous simultaneously hermaphroditic land snail Achatina fulica (Férussac) (Stylommato-phora: Achatinidae). J Moll Stud 62:101-111
131. Tomlinson J (1966) The advantages of hermaphroditism and parthenogenesis. J Theor Biol 11:54-58
132. Trowbridge CD (1995) Hypodermic insemination, oviposition, and embryonic development of a pool-dwelling ascoglossan (= sacoglossan) opisthobranch: Er-colania felina (Hutton, 1882) on New Zealand shores. Veliger 38:203-211
133. Tsitrone A, Duperron S, David P (2003) Delayed selfing as an optimal mating strategy in preferentially outcrossing species: theoretical analysis of the optimal age at first reproduction in relation to mate availability. Am Nat 162:318-331
134. Velando A, Eiroa J, Domínguez J (2008) Brainless but not clueless: earthworms boost their ejaculates when they detect fecund non-virgin partners. Proc R Soc Lond B 275:1067-1072
135. Vizoso DB, Schärer L (2007) Resource-dependent sex-allocation in a simultaneous hermaphrodite. J Evol Biol 20:1046-1055
136. Vreys C, Michiels NK (1997) Flatworms flatten to size up each other. Proc R Soc Lond B 264:1559-1564
137. Vreys C, Michiels NK (1998) Sperm trading by volume in a hermaphroditic flat-worm with mutual penis intromission. Anim Behav 56:777-785
138. Warner RR (1975) The adaptive significance of sequential hermaphroditism in animals. Am Nat 109:61-82
139. Webster JP, Gower CM (2006) Mate choice, frequency dependence, and the maintenance of resistance to parasitism in a simultaneous hermaphrodite. Integr Comp Biol 46:407-418
140. Webster JP, Hoffman JI, Berdoy M (2003) Parasite infection, host resistance and mate choice: battle of the genders in a simultaneous hermaphrodite. Proc R Soc Lond B 270:1481-1485
141. Wedell N, Gage MJG, Parker GA (2002) Sperm competition, male prudence and sperm-limited females. Trends Ecol Evol 17:313-320
142. Wethington AR, Dillon RT Jr (1996) Gender choice and gender conflict in a non-reciprocally mating simultaneous hermaphrodite, the freshwater snail, Physa. Anim Behav 51:1107-1118
143. Yusa Y (1996) The effects of body size on mating features in a field population of the hermaphroditic sea hare Aplysia kurodai Baba, 1937 (Gastropoda: Opist-hobranchia). J Moll Stud 62:381-386