Structure of the seismosensory system of <Emphasis Type="Italic">Psettodes erumei</Emphasis> (Psettodidae,Pleuronectiformes)

The structure of the seismosensory system of Psettodes erumei was studied. General and specific features in comparison with the previously studied representatives of the suborder Pleuronectoidei were revealed. Similarity is manifested in the presence of four main head canals, coronal commissure, interrupted supratemporal commissure transformed into a supratemporal canal, and one trunk canal developed on both sides of the body. The seismosensory system of Psettodes erumei is characterized by several plesiomorphous characters: the presence of a sensory segment in lacrimale of the eyed side and supracleithrum, the absence of disruptions in all sensory canals, and a strong branching of cutaneous canaliculi. Specific features of P. erumei involve the presence of a large number of fontanels on angulo-articulare, connection on the eyed side of CIO sites in lacrimale and infraorbitale, and the underdevelopment of the bony vault of the sensory canal in praeoperculum.     

Mitogenomics of the suborder Cottoidei (Teleostei: Perciformes): Improved assemblies,mitogenome features,phylogeny, and ecological implications

We determined the mitogenome of Cyclopterus lumpus using a hybrid sequencing approach, and another four closely related species in the Liparidae based on available next-generation sequence data. We found that the mitogenome of C. lumpus was 17,266 bp in length, where the length and organisation were comparable to those reported for cottoids. However, we found a GC-homopolymer region in the intergenic space between tRNA^Leu2 and ND1 in liparids and cyclopterids. Phylogenetic reconstruction confirmed the monophyly of infraorders and firmly supported a sister-group relationship between Cyclopteridae and Liparidae. Purifying selection was the predominant force in the evolution of cottoid mitogenomes. There was significant evidence of relaxed selective pressures along the lineage of deep-sea fish, while selection was intensified in the freshwater lineage. Overall, our analysis provides a necessary expansion in the availability of mitogenomic sequences and sheds light on mitogenomic adaptation in Cottoidei fish inhabiting different aquatic environments.     

Phylogeny of the snailfishes (Teleostei: Liparidae) based on molecular and morphological data

Liparidae (snailfishes) is one of the most diverse and abundant fish families in polar and deep-sea habitats. However, the evolution of this family is poorly known because of the rarity of many species and difficulties in scoring morphological characters. We perform phylogenetic analyses of Liparidae using sequences from two mtDNA genes, 16S (585 bp) and cytochrome b (426 bp), and 84 morphological characters from 24 species of Liparidae and 4 species of Cyclopteridae (outgroup). The present study confirms earlier hypotheses that the shallow-water genera, such as Liparis and Crystallichthys, occupy basal positions and that deep-water genera, such as Careproctus, Elassodiscus, Rhinoliparis, Paraliparis, Rhodichthys and Psednos, are increasingly derived. The later two genera form a terminal clade which does not include Paraliparis. The topology shows that the family has undergone a reductive type of evolution, with a gradual loss of characters (e.g. sucking disc/pelvic fins, pseudobranchial filaments, skin spinules). Nectoliparis, which had previously been placed either as the basal most genus or among the most derived genera, are found to occupy the most basal position among the taxa analyzed. This result indicates that the sucking disc has been lost at least twice during the evolution of the Liparidae. The basal position of Nectoliparis is supported by its plesiomorphic otolith morphology, whereas an advanced overgrown otolith ostium, unique among teleosts, is found to be apomorphic for a clade containing the derived genera: Paraliparis, Psednos, Rhinoliparis and Rhodichthys. We also identify the presence of probable nuclear inserts of mitochondrial DNA (Numts) in three species of Careproctus and in Elassodiscus caudatus.     

New deepwater species of the genus <Emphasis Type="Italic">Gobiopsis</Emphasis> (Gobiidae) from the Tropical Western Pacific

A new species, Gobiopsis uranophilus sp. n., is described off the Anambas Islands, South China Sea, from a depth of 73 m. The species is similar to the deepwater Japanese species G. namnas, but it differs in the dorsal orientation of the eyes, total absence of pores of the seismosensory system on the head, number of fin rays, and other characters. The similar patterns of the two species (presence of scales on the sides of the head, absence of the barbel-shaped appendages on the head, and large scales on the body), most likely, are connected with their adaptation to deepwater habitats.     

Hemoglobin structure/function and globin-gene evolution in the Arctic fish Liparis tunicatus

The importance of the Arctic, in contributing to the knowledge of the overall ensemble of adaptive processes influencing the evolution of marine organisms, calls for investigations on molecular adaptations in Arctic fish. Unlike the vast majority of Antarctic Notothenioidei, several Arctic species display high hemoglobin multiplicity. The blood of four species, the spotted wolffish of the family Anarhichadidae and three Gadidae, contains three functionally distinct major components. Similar to many Antarctic notothenioids, Arctic Liparis tunicatus (suborder Cottoidei, family Liparidae) has one major hemoglobin (Hb 1) accompanied by a minor component (Hb 2). This paper reports the structural and functional characterisation of Hb 1 of L. tunicatus. This hemoglobin shows low oxygen affinity, and pronounced Bohr and Root effects. The amino-acid sequence of the beta chain displays an unusual substitution in NA2 (beta2) at the phosphate-binding site, and the replacement of Val E11 (beta67) with Ile. Similar to some Antarctic fish Hbs, electron paramagnetic resonance spectra reveal the formation of a ferric penta-coordinated species even at physiological pH. The amino-acid sequences have also been used to gain insight into the evolutionary history of globins of polar fish. L. tunicatus globins appear close to the notothenioid clades as predicted by teleostean phylogenies. Close phylogenetic relationships between Cottoidei and Notothenioidei, together with their life style, seem to be the main factor driving the globin-sequence evolution.     

Comparative osteology of <Emphasis Type="Italic">Cyclopsis tentacularis</Emphasis> (Cyclopteridae,Scorpaeniformes)

The structure of the skeleton of Cyclopsis tentacularis, an endemic species from the northern part of the Sea of Okhotsk, is studied for the first time. Generally, it corresponds to that in other representatives of Cyclopteridae. The differences in structure of Cyclopsis and of other investigated cyclopterids are both plesiomorphic and apomorphic. The plesiomorphic ones are comprised of sutural articulation of pteroticum and prooticum, spiny ray in the beginning of D2, berycoid opening in ceratohyale, bony pharyngobranchiale 2, emergination in the anterior margin of scapula, and postcoracoid opening in coracoideum. The apomorphic ones are separation of parietalia, absence of bony basibranchialia, presence of emargination in the posterior margin of supracleithrum, and reduction of several last epipleural ribs. The presence of numerous plesiomorphies does not confirm Ueno’s viewpoint (Ueno, 1970) on the advanced position of Cyclopsis in the family Cyclopteridae. Final conclusions on the position of Cycloposis in the system of cyclopteridae and of the system of this family itself may be made only after proper investigation of the external morphology and osteology of all genera of Cyclopteridae.     

Phylogenetics and evolution of Capitata (Cnidaria: Hydrozoa), and the systematics of Corynidae

Nawrocki, A. M., Schuchert, P. & Cartwright, P. (2009). Phylogenetics and evolution of Capitata (Cnidaria: Hydrozoa), and the systematics of Corynidae.—Zoologica Scripta, 39, 290–304. Generic‐ and family level classifications in Hydrozoa have been historically problematic due to limited morphological characters for phylogenetic analyses and thus taxonomy, as well as disagreement over the relative importance of polyp vs. medusa characters. Within the recently redefined suborder Capitata (Cnidaria: Hydrozoa: Hydroidolina), which includes 15 families and almost 200 valid species, family level relationships based on morphology alone have proven elusive, and there exist numerous conflicting proposals for the relationships of component species. Relationships within the speciose capitate family Corynidae also remain uncertain, for similar reasons. Here, we combine mitochondrial 16S, and nuclear 18S and 28S sequences from capitate hydrozoans representing 12 of the 15 valid capitate families, to examine family level relationships within Capitata. We further sample densely within Corynidae to investigate the validity of several generic‐level classification schemes that rely heavily on the presence/absence of a medusa, a character that has been questioned for its utility in generic‐level classification. We recover largely congruent tree topologies from all three markers, with 28S and the combined dataset providing the most resolution. Our study confirms the monophyly of the redefined Capitata, and provides resolution for family level relationships of most sampled families within the suborder. These analyses reveal Corynidae as paraphyletic and suggest that the limits of the family have been underestimated. Our results contradict all available generic‐level classification schemes for Corynidae. As classification schemes for this family have been largely based on reproductive characters such as the presence/absence of a medusa, our results suggest that these are not valid generic‐level characters for the clade. We suggest a new taxonomic structure for the lineage that includes all members of the newly redefined Corynidae, based on molecular and morphological synapomorphies for recovered clades within the group.     

Specific features of the seismosensory system and their use in the systematics of five families of the order pleuronectiformes

The structure of the seismosensory system (SSS) was studied in 23 species of 13 genera from the families Rhombosoleidae, Poecilopsettidae, and Samaridae, and a comparison and generalization of the obtained data with those published previously for the families Psettodidae and Pleuronectidae was performed. It was shown that the individual variability of SSS does not concern topography of canals, being manifested in the variation of the number of pores in particular canals. Interspecific differences also concern mainly the number of pores, and revealing these differences requires, as a rule, statistic methods. Considerable differences were found between genera, so that each of the 40 studied genera can be characterized by a unique combination of SSS characters whose polarization was established on the basis of a reduction trend of SSS transformations common for bony fish. The maximum number of plesiomorphies of SSS was found in the genus Psettodes (Psettodidae). In the framework of the family Pleuronectidae, the most generalized structure of SSS was found in representatives of the subfamily Hippoglossinae, and the most advanced, in Pleuronectinae. In the family Rhombosoleidae, the most generalized structure of SSS is in the genus Oncopterus, the remaining representatives of the family Rhombosoleidae are characterized by a different degree of its reduction. In rather closely related families Poecilopsettidae and Samaridae, SSS is considerably reduced, which may be connected with the miniatuarization of their representatives. A small number of considered characters and a high level of homoplasia hinders their use in cladistic study; however, considerable differences between the studied genera and a low interspecific variation permits for the considering of specific features of SSS as valuable diagnostic characters of genera, and the degree of reduction of this system can indicate the relative degree of advancement of a specific taxon of Pleuronectiformes.     

Larval morphology and phylogenetic position of Micromalthus debilis LeConte (Coleoptera: Micromalthidae)

Abstract External and internal structures of the cerambycoid and triungulin larvae of Micromalthus debilis are described and compared to features found in larvae of other groups of Coleoptera. The morphological data are evaluated with respect to the systematic position of Micromalthidae. A cladistic analysis was carried out with fifty characters. Micromalthidae are not closely related to Lymexylidae (Polyphaga: Cucujiformia) but belong to Archostemata, which is confirmed as a monophyletic unit. Micromalthidae are specialized in terms of morphology and life cycle and are characterized by a considerable number of larval autapomorphies. Their sister-group relationship with Cupedidae is supported by several apomorphic features, which are probably correlated with xylobiontic habits: head transverse and strongly rounded laterally, absence of stemmata, shortened antennae, presence of sternal asperities and presence of eversible lobes of segment IX. Cupedidae is monophyletic and Priamca is the sister group of the remaining genera of Cupedidae included in the analysis. A closer relationship between Tenomerga and Rhipsideigma is supported by several larval synapomorphies. The ancestral life style of larvae of Archostemata was probably xylobiontic. This is suggested by derived groundplan features of the suborder, which are also found in larvae of non-related, wood-associated families.     

Phylogenetic position of the family Trichodontidae (Teleostei: Perciformes), with a revised classification of the perciform suborder Cottoidei

The phylogenetic relationships of the family Trichodontidae and suborder Cottoidei (and zoarcoid Bathymasteridae) are reconstructed morphologically. The monophyly of the Trichodontidae, Cottoidei, and Zoarcoidei is unambiguously supported by 14 synapomorphies, including 1 newly recognized (and also 4 synapomorphies when ACCTRAN is accepted). It is assumed that the Trichodontidae is deeply nested within the Cottoidei, and the family and Cottoidea plus Cyclopteroidea have a sister relationship, supporting a previously inferred molecular phylogenetic hypothesis. We propose that the Trichodontidae is placed into the cottoid superfamily Trichodontoidea.     

Seismosensory system of the Lower Amur rayling <Emphasis Type="Italic">Thymallus tugarinae</Emphasis> (Thymallidae) from the Anyui River

Data on specific features of the seismosensory system of the Lower Amur grayling Thymallus tugarinae from the Anyui River (basin of the Lower Amur) are provided. According to the number of openings in canals of the seismosensory system, individuals from the middle course significantly differ from graylings from the lower course in greater values of interpopulation diversity and fluctuating asymmetry. According to the number of pores of canals of the seismosensory system, the Lower Amur grayling differs from the East Siberian T. arcticus pallasi, Kamchatka T. a. mertensii, and Alaska T. a. signifer graylings.     

Phylogeny and Systematics of Multituberculate Mammals

We present a synopsis of high-rank multituberculate systematicsand a manually generated cladogram illustrating multituberculate interrelationships. We divide the Multituberculata into the paraphyletic suborder 'Plagiaulacida', an apparently monophyletic suborder Cimolodonta, and one family incertae sedis. Within 'Plagiaulacida' we recognise three informal lines: paulchoffatiid (three families), plagiaulacid (three families) and allodontid (two families and the genus Glirodon). The Cimolodonta are divided into an informal Paracimexomys group; three superfamilies: Ptilodontoidea, Djadochtatherioidea (new), and Taeniolabidoidea (restricted to Taeniolabididae); and five families (superfamily incertae sedis): Eucosmodontidae, Microcosmodontidae, Cimolodontidae, Boffiidae, and Kogaionidae; and some genera incertae sedis. New characters used in our analysis are (1) a tendency of molar cusps to coalesce; and (2) ornamentation of grooves, pits, and ridges on the molars. We argue that the Ptilodontoidea, and less certainly also the Cimolodontidae and Boffiidae, might have originated from amongthe plagiaulacid line, a possible intermediate link being the Paracimexomys group. The remaining Cimolodonta might have originated from unknown members of the Paracimexomys group with separated molar cusps and smooth enamel. The origin of two types of prismatic enamel and a relationship between them are stumbling blocks in understanding the origin of the Cimolodonta; we conclude that microprismatic enamel made its appearance only once. Revised diagnoses of high-rank multituberculate taxa, including lists of all known genera, are given.     

System of the class Holothuroidea

Various interpretations of the holothurian system and phylogeny are critically reviewed and the main characters that form the basis of the existing systematics of this group are analyzed. A system of holothurians based on thorough analysis of their morphology and anatomy is proposed. Four subclasses are recognized in the class Holothuroidea: Arthrochirotacea, Synaptacea, Elpidiacea, and Holothuriacea. The subclass Arthrochirotacea includes the extinct Paleozoic order Arthrochirotida. The subclass Synaptacea includes the order Synaptida with two suborders and three families. The subclass Elpidiacea includes the order Elasipodida with four families. The subclass Holothuriacea includes four orders: Aspidochirotida with five families; Dendrochirotida with 15 families (14 extant and one extinct); Molpadiida with three families; Gephyrothuriida with one family and two genera Gephyrothuria and Hadalothuria. The order Gephyrothuriida is re-established. The order Dactylochirotida Pawson et Fell, 1965 is synonymized under the order Dendrochirotida. A new suborder Cucumariina and new family Mesothuriidae are described. The family Vaneyellidae is synonymized under the family Cucumariidae. Four subfamilies are classified as families: Cladolabidae, Sclerothyonidae, Monilipsolidae, and Thyonidiidae.     

Cotylea (Polycladida): a cladistic analysis of morphology

Abstract. Polyclad flatworms are acoelomate bilaterians found in benthic communities worldwide, predominantly in marine environments. Current polyclad systematics is unstable, with two non-concordant classification schemes resulting in a poor understanding of within-group relationships. Here we present the first phylogenetic framework for the suborder Cotylea using a morphological matrix. Representatives of 34 genera distributed among all cotylean families (except four, excluded due to their dubious taxonomic status) were investigated. The number of families included ranges from a conservative eight to a revisionary 11. Outgroup analysis indicated that the suborder is monophyletic and defined by the presence of a ventral adhesive structure, a short posteriorly positioned vagina, and cement glands. Of the eight to 11 families included, we confirmed that three were monophyletic: Boniniidae, Prosthiostomidae, and Pseudocerotidae. Boniniidae was consistently recovered as the sister group to other Cotylea, based on the retention of the plesiomorphic Lang's vesicle. The clade consisting of Anonymus, Marcusia , and Pericelis is sister to the Boniniidae and the rest of the Cotylea. Above this clade there is little resolution at the base of the sister group. The Euryleptidae are found to be paraphyletic and give rise to the Pseudocerotidae. Neither classification scheme received unequivocal support. The intrafamilial relationships of the diverse Pseudocerotidae and Euryleptidae were examined. Color pattern characters (used for species identification) were highly homoplasious but increased cladogram resolution within genera. The monophyly of seven genera within the Pseudocerotidae and Euryleptidae was not supported and many genera showed no autapomorphies, highlighting the need for taxonomic revision of these families.     

基于发生学与形态学资料对盾纤目纤毛虫(原生动物,纤毛门)的系统修订

根据细胞分裂中口器发生的类型、形态结构特征及近祖-衍化性状的推断,利用简约性原理及聚类分析方法对盾纤目纤毛虫的目下系统关系做了探讨和修订.主要结论包括:1)确认该类群为一目级的单源发生系,下含3个亚目:嗜污亚目、帆口亚目、触毛亚目;2)嗜污亚目经廓清认定了52个有效属,分别隶属重新调整后的13个科;3)帆口亚目经厘定共有20个有效属,调整入7个科中;4)触毛亚目3个科,包含13个地位明确的属.文中对前人所建系统中不尽合理、存疑以及混乱之处做了讨论和建议性修正.     

Relationships and position of the genus <Emphasis Type="Italic">Neozoarces</Emphasis> of the subfamily neozoarcinae in the system of the suborder Zoarcoidei (Pisces,Perciformes) by molecular-genetic data

Using the method of molecular-genetic analysis, we investigated the genus Neozoarces (subfamily Neozoarcinae) to reveal its relationships and position in the system of the suborder Zoacoidei. Comparison with representatives of other families of this suborder demonstrated that the lowest level of differences is observed between Neozoarces and subfamilies of the family Zoarcidae (the mean value of genetic divergence is 11.9%) with which it forms a general cluster on the phylogenetic tree. From representatives of the family Stichaeidae, Neozoarces differs at the same level (13.9%) as from the families Bathymasteridae, Pholidae, Ptilichthyidae, and Zaproridae (14.0%). The results of investigations confirm the viewpoint suggested by Makushok (1961) who included, for the first time, the subfamily Neozoarcinae to the family Zoarcidae on the basis of comparative morphological investigation of these groups.     

Sperm structure of Trichoptera. III. Hydropsychidae,polycentropodidae and philopotamidae (Annulipalpia)

Spermatozoa from 9 species belonging to 3 families of trichopteran suborder Annulipalpia (Philopotamidae : Philopotamus ludificatus, P. montanus, Wormaldia occipitalis, W. copiosa; Polycentropodidae: Plectrocnemia geniculata, Polycentropus mortoni, P. irroratus, Cyrnus trimaculatus; Hydropsychidae: Hydropsyche pellucidula) were studied by light, scanning, and transmission electron microscopy. The absence of axonemal dynein arms and a consequent sperm immotility are characteristic of the species studied. The presence of 7, rather than 2, central microtubules is shared by Polycentropodidae and some Philopotamidae. A greater variability in the sperm axoneme was found within Philopotamidae than in the other families. The species of the genus Wormaldia have an axial vesicle rather than microtubules and their axonemes have a 9 + 9 + 0 or 13 + 13 + 0 pattern. Hydropsychidae have spermatozoa provided with numerous finger-like appendages containing microtubular doublets. The progressive loss of sperm flagellum and motility within the group is discussed.     

Morphology of male genitalia in lice and their relatives and phylogenetic implications

Abstract.  Lice (Insecta: Phthiraptera) have long been considered to compose a monophyletic group of insects on the basis of external morphological characteristics. However, a recent phylogenetic analysis of 18S rDNA sequences suggested that 'Phthiraptera' have arisen twice within the order Psocoptera (booklice and barklice). The external features of lice are highly specialized to a parasitic lifestyle, and convergence may be frequent for such characters. To provide a further test between traditional and recent molecular-based phylogenetic hypotheses, a phylogenetic analysis of lice and relatives based on morphological characters that are independent from the selective pressures of a parasitic lifestyle is needed. Here, we examined the morphology of the male phallic organ in lice and relatives ('Psocoptera': suborders Troctomorpha and Psocomorpha) and detected some novel modifications that were stable within each group and useful for higher level phylogenetic reconstruction. Phylogenetic analysis based on these characters provided a concordant result with the 18S-based phylogeny. In particular, the apomorphic presence of articulations between the basal plate, mesomere and ventral plate (= sclerite on the permanently everted endophallus) is observed consistently throughout the psocid families Pachytroctidae and Liposcelididae and the louse suborder Amblycera, providing support for a clade composed of these three groups, although possible homoplasy was detected in some Ischnocera. This is the first study to provide morphological support for the polyphyly of lice.     

TAXONOMIC COMMENTS ON THE EURYLAIMIDAE

On the basis of supposed differences in the shape of the spina externa of the sternum, the number of cervical vertebrae, the deep plantar tendons, the quadrato-jugal articulation, and the size of the hallux, the Eurylaimidae were put in a separate suborder, the Eurylaimi. All of these characters are now shown to be variable within the family or shared with other suboscine families. It is recommended that the subordinal designation “Eurylaimi” be abandoned and that the family be included in the suborder Tyranni. A number of characters point to the Cotingidae as the nearest possible extant relatives of the Eurylaimidae. The Eurylaimidae consist of a number of unrelated genera with several relict species, and probably represent the remains of an ancient, once more widespread group that became isolated and gave rise to the suboscine fauna in South America while being largely replaced by oscines in the Old World. Recognition of subfamilies within the Eurylaimidae is discouraged. Smitkornis should be considered the most advanced of the eurylaimids. The sequence of suboscine families is discussed and a rearrangement is suggested.