Contributions to Zoology, 67 (2) 125-141 (1997)Christopher C. Tudge: Phylogeny of the Anomura (Decapoda, Crustacea): Spermatozoa and spermatophore morphological evidence

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Appendix A Spermatozoal Characters

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Character 1. Origin of microtubular arms. The bundles of microtubules, representing the bases of the microtubular arms, can be either nuclear in origin or develop and emerge from the cytoplasm. The hairy stone crab Lomis hirta has microtubules in both the nucleus and the cytoplasm but because spermiogenesis has not been studied, their origin remains equivocal. The brachyuran crabs do not possess microtubular arms and so the character has been scored as secondarily absent. (Nuclear origin = 0, cytoplasmic origin = 1, secondarily absent = 2.)

Character 2. Number of microtubular arms. The number of microtubular arms in the mature spermatozoa of the thalassinoids, porcellanids, and hippoids is four or more while representatives from the Paguroidea and Galatheoidea (with the exception of the Porcellanidae) always have only three. The exact number of microtubular arms is not known for Thalassina squamifera, Lomis hirta, and Pisidia longicornis. As above, this character has been scored as secondarily absent in Portunus pelagicus. (More than 3 arms = 0, 3 arms = 1, secondarily absent = 2.)

Character 3. Proportion of the acrosome vesicle that the cytoplasm envelops. The acrosomal vesicle may be totally embedded in the cytoplasm (except for the opercular region), significantly embedded, or the acrosomal vesicle may be superior to the cytoplasm with only its most posterior portion embedded. (All of the acrosomal vesicle embedded [except operculum] = 0, half or more than half of the acrosomal vesicle embedded = 1, posterior portion only embedded = 2.)

Character 4. Presence and extent of perforatorial chamber. A distinct perforatorial chamber appears to be absent in the spermatozoa of Trypaea australiensis, Panulirus argus, and Thenus orientalis but present in the remaining species studied. In the species with a perforatorial chamber, this structure can extend from the base of the acrosome vesicle to a subterminal position below the operculum (post-equatorial) or terminate at or below the mid-point of the acrosome vesicle (pre-equatorial). (Perforatorial chamber absent = 0, post-equatorial = 1, pre-equatorial = 2.)

Character 5. Perforatorial chamber shape. For those species with a perforatorial chamber, it can assume one of three forms: (1) a bulbous posterior section with a thin, tapering anterior projection, (2) a columnar or basically uniform cylindrical perforatorial chamber, or (3) entirely bulbous or having the anterior region swollen into a bulbous area. (Perforatorial chamber absent = 0, perforatorial chamber bulbous posteriorly and tapering anteriorly = 1, columnar or cylindrical = 2, entirely bulbous or bulbous anteriorly = 3.)

Character 6. Presence and form of microvillar projections. Microvillar projections are small finger-like structures that extend laterally from the perforatorial chamber wall into the posterior region of the perforatorial chamber in some anomuran representatives. When the microvillar projections are present, they are either short and tuberculous or longer and filamentous. (Microvillar projections absent = 0, short and tuberculous = 1, long and filamentous = 2.)

Character 7. Ornamentation of perforatorial chamber walls. The walls of the perforatorial chamber (if one is present) may or may not be ornamented with longitudinal grooves or septa. (Perforatorial chamber absent = 0, perforatorial chamber walls smooth = 1, shallow longitudinal corrugations = 2, prominent longitudinal septa = 3.)

Character 8. Form of the anterior tip of the perforatorial chamber. In the majority of species the anterior end or apex of the perforatorial chamber (if one is present) is entire but in representatives from the genus Calcinus and the hippid, Hippa pacifica the perforatorial chamber divaricates into two or more perforatorial points or fingers. (Perforatorial chamber absent = 0, anterior end of perforatorial chamber entire = 1, separated into two or more points or fingers = 2.)

Character 9. Perforatorial chamber contents. Where one is present, the perforatorial chamber in the majority of taxa does not contain any structures but has a homogeneous or heterogeneous granular matrix. Exceptions are the presence of tortuous perforatorial tubules or a longitudinal septum which ‘hangs‘ inside the chamber. (Perforatorial chamber absent = 0, perforatorial chamber contents without tubules or septum = 1, prominent tubules = 2, prominent dividing septum = 3.)

Character 10. Acrosome vesicle dimensions. The acrosome vesicle shapes exhibited by the various taxa are arranged into four categories. (1) Subspheroidal acrosome with length to width ratios less than 1.0. (2) Spherical to ovoid acrosome, encompassing the acrosome length to width ratios of 1.0 - 1.5. (3) Ovoid to oblong-ovoid acrosome with length to width ratios of 1.6 - 2.5. (4) Oblong-ovoid to elongate cylindrical acrosome with length to width ratios of 2.6 - 5.0. (Acrosomal vesicle length to width ratios < 1.0 = 0, 1.0 - 1.5 = 1, 1.6 - 2.5 = 2, 2.6 - 5.0 = 3.)

Character 11. Acrosome vesicle contents. The spermatozoa of Axius glyptocercus, Trypaea australiensis, Panulirus argus, Thenus orientalis, and less so Lomis hirta exhibit no concentric zonation of the acrosome vesicle contents, while the remaining taxa show distinct concentric zonation. (Concentric zonation absent = 0, present = 1.)

Character 12. Operculum form. The electron-dense operculum may be centrally perforate or entire. In Lomis hirta there is more than one perforation and the operculum appears interrupted. The condition of the operculum is unknown in Thenus orientalis. (Operculum imperforate = 0, perforate = 1.)

Character 13. Thickened ring. The brachyuran crabs have a dense ring at the posterior end of the acrosome vesicle surrounding the perforatorial chamber base (see Jamieson, 1991a). A dense ring of similar appearance is present in the same position in the spermatozoa of Thalassina squamifera. (Thickened ring absent = 0, present =1.)

Character 14. Acrosome ray zone. The acrosome ray zone is a modified zone within the acrosome vesicle that has the appearance, in transverse section, of dark and light radiating bands. This zone may occupy the majority of the acrosome vesicle contents or may be smaller in extent. Some taxa (Calcinus laevimanus, Cancellus sp., and Pagurus prideaux) have a similar-looking zone but the homology is uncertain. (Acrosome ray zone absent = 0, present = 1.)

Character 15. Subopercular zone. The subopercular zone (when present) is an homogeneous, coarsely granular region that is directly below or often fills the concavity of the operculum and may extend for some distance down the acrosome vesicle. This zone may be divided into two or more separate regions. (Subopercular zone absent = 0, entire = 1, divided into two or more regions = 2, divided into three or more regions = 3.)

Character 16. Dense perforatorial ring. The dense perforatorial ring is an electron-dense zone that occurs around the posterior bulbous region of the perforatorial chamber in the representatives of the genus Clibanarius only. (Dense perforatorial ring absent = 0, present = 1.)

Character 17. Fibrillar acrosome core. The fibrillar acrosome core is the anterior modification of the inner acrosome zone in the spermatozoa of Diogenes custos and D. pallescens into an elongate fibrillar structure which spirals apically. (Fibrillar acrosome core absent = 0, present = 1.)

Character 18. Reticulated acrosome zones. The reticulated acrosome zones are one or more concentric zones, towards the centre of the acrosome vesicle, which have a reticulated appearance in both transverse and longitudinal section. They are found in most studied representatives of the families Paguridae and Parapaguridae. (Reticulated acrosome zones absent = 0, present = 1.)

Character 19. Lacunar sheath. The lacunar sheath or vesiculated sheath has been observed in the spermatozoa of the pagurid Porcellanopagurus sp. and is a thin, vesiculated or faintly loculated cylinder that tightly surrounds the perforatorial chamber at the midpoint of the acrosome vesicle. (Lacunar sheath absent = 0, present = 1.)

Character 20. Position of microtubular arms. Where they are present, the microtubular arms emerge from the cytoplasm surrounding the acrosome vesicle at the posterior end of the acrosome vesicle in nearly all investigated taxa, except for Xylopagurus sp., where they emerge in an anterior position. (Microtubular arms posteriorly situated = 0, anteriorly situated = 1, secondarily absent = 2.)

Character 21. Inner acrosome zone. The inner acrosome zone, when present, is generally the innermost zone of the concentric series and is homogeneous, finely granular and of moderate electron density. The zone may be divided into two distinct regions. The imperfect fixation of Thalassina squamifera does not allow a decision to be made concerning the presence or form of an inner acrosome zone. (Inner acrosome zone absent = 0, entire = 1, divided = 2.)

Character 22. Microtubular core. The microtubular core is the large bundle of longitudinally arranged microtubules that occupy the central axis of the elongate spermatozoa in the porcellanid species Aliaporcellana suluensis, Pisidia longicornis, and Polyonyx transversus. (Microtubular core absent = 0, present = 1.)

Character 23. Dense perforatorial cone. The dense perforatorial cone occurs as an electron-dense, thin layer enveloping the anterior region of the perforatorial chamber in the porcellanids and, questionably, the pagurid Porcellanopagurus sp. It is usually separated from the perforatorial chamber by a thin layer of inner acrosome zone, is perforate at the perforatorial chamber apex and may extend to the base of the perforatorial chamber. (Dense perforatorial cone absent = 0, present = 1.)

Character 24. Posterior perforatorial ring. The posterior perforatorial ring is present only in the investigated members of the family Porcellanidae where it occurs as a dense ring around the perforatorial chamber in the posterior region of the acrosome vesicle. (Posterior perforatorial ring absent = 0, present = 1.)

Character 25. Opercular ridge. The opercular ridge is a lateral extension on the external surface of the electron-dense operculum in the two investigated species of the genus Petrolisthes. (Opercular ridge absent = 0, present = 1.)

Character 26. Tubular ring. The tubular ring is a structure found in the acrosome vesicle of Petrolisthes armatus and P. lamarckii. It encircles the perforatorial chamber at the mid-point of the acrosome vesicle and is very electron-dense, but has somewhat paler electron-lucent tubules running concentrically through it. (Tubular ring absent = 0, present = 1.)

Spermatophore Characters

Character 27. Spermatophore form. The spermatophores in the investigated taxa can assume one of three forms. (1) A tubular spermatophore extruded in the size and shape of the vas deferens. (2) A pedunculate, tripartite spermatophore consisting of an ampulla attached to a pedestal or base by a stalk of variable length. (3) A spherical to ovoid capsular spermatophore. In Axius glyptocercus, Thalassina squamifera, Eumunida sternomaculata, and Polyonyx transversus the spermatophore morphology is unknown. (Spermatophores tubular = 0, pedunculate = 1, capsular = 2.)

Character 28. Spermatophore ridge. The spermatophore ridge is a raised and thickened area of the spermatophore wall where the two halves of the ampulla split to release the contained spermatozoa. The centre of the spermatophore ridge has a break in the spermatophore wall structure. (Spermatophore ridge absent = 0, present = 1.)

Character 29. Presence of accessory ampullae. The spermatophores of the investigated members of the genus Pagurus (with the possible exception of P. chevreuxi) and the parapagurid Sympagurus sp. have a smaller accessory ampulla present at the base of the main ampulla. An accessory ampulla may also be present in the chirostylid Uroptychus sp. (Spermatophores with accessory ampulla and main ampulla = 0, main ampulla only = 1.)

Character 30. Presence of tubular extension. The spermatophores of Petrolisthes lamarckii and P. armatus have a long tubular extension projecting from the distal end of the ampulla. (Spermatophore ampulla without tubular extension = 0, with tubular extension = 1.)

Character 31. Form of stalk in pedunculate spermatophores. In the taxa which possess pedunculate spermatophores the stalk can assume one of three forms. (1) An extremely short, almost non-existent, pseudo-stalk. (2) A short, thick stalk. (3) A long, thin stalk. (Spermatophores tubular or capsular = 0, spermatophores pedunculate with small pseudo-stalk = 1, pedunculate with short, thick stalk = 2, pedunculate with long, thin stalk = 3.)

Character 32. Spermatophore wall ultrastructure. Where the ultrastructure of the spermatophore wall is known, three distinct forms occur. The spermatophore wall can be (1) homogeneously granular in appearance, (2) heterogeneously granular, or (3) fibrillar. (Spermatophore wall ultrastructure homogeneously granular = 0, heterogeneously granular = 1, fibrillar = 2.)

Appendix B

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Data Matrix in ASCII file [0 = 0/1 or an equivocal character state assignment]