A fossil osteoglossoid fish from Tanzania (E. Africa)

A new genus and species ( Singida jacksonoides ) and a new family (Singididae) of osteoglossoid fishes are described from the lacustrine deposits in Tanzania which have already yielded the primitive clupeomorph Palaeodenticeps. Singida differs from all Osteoglossomorpha in being toothless. Although it shows some affinity with the living Asiatic genus Scleropages , it also exhibits certain characters, particularly in the caudal skeleton, which are usually associated with the recent and fossil Hiodontoidei of North America. Singida shows little affinity with either of the living African genera of Osteoglossoidei. The age of the Singida deposits is unknown, but the fish fauna suggests a Palaeogene (? Oligocene) age.     

A fossil clupeomorph fish from the Albian of the Northwest Territories of Canada, with notes on cladistic relationships of clupeomorphs

A primitive clupeomorph, Erichalcis arcta gen. et sp. nov. is described from the Albian of Northwest Territories, Canada. Erichalcis is uniquely specialized among clupeomorphs in the presence of enlarged lateral line scales and in the structure of the caudal skeleton. Erichalcis is classified as Clupeiformes incertae sedis. The two recognized suborders, Clupeoidei and Denticipitoidei are examined with respect to primitive and derived character states. It is concluded that the clupeoids and denticipitoids are divergently specialized in details of the union between the supraorbital and infraorbital sensory canals and the recessus lateralis. It is further suggested that the reduction in size and the posterior shift of the dermosphenotic in clupeoids is correlated with an upper division of the levator arcus palatini muscle and an antero-dorsal process on the hyomandibular. Cladistic relationships of some Cretaceous clupeomorphs are proposed and it is suggested that Diplomystus brevissimus Cope not be included in the Clupeoidei.     

The relationships of Gasteroclupea branisai Signeux, 1964, a freshwater double-armored herring (Clupeomorpha,Ellimmichthyiformes) from the Late Cretaceous-Paleocene of South America

The clupeomorph fish Gasteroclupea branisai Signeux, 1964 from the Late Cretaceous-Paleocene of El Molino Formation, Cayara locality, Bolivia is redescribed in detail. This South American double-armored herring is the sole member of the family Gasteroclupeidae and exhibits a unique combination of features (skull roof ornamented with fine tubercles, beryciform foramen, endopterygoid teeth, about 16–18 supraneurals, a series of 35–38 predorsal and 40 ventral scutes, median fins small and containing 12–14 rays) that clearly supports its assignment to the extinct clupeomorph order Ellimmichthyiformes. G. branisai shares a number of synapomorphies with Sorbinichthys elusivo and S. africanus (five hypurals, second hypural autogenous, distal end of the second uroneural not reaching the distal end of the first uroneural) with which it forms a monophyletic assemblage recognized herein for the first time as the new suborder Sorbinichthyoidei. The peculiar morphology of Gasteroclupea that is characterized by having an extremely deep abdominal profile, hypertrophied coracoid, and elongated pectoral fins, resembles in many aspects the body plan of extant freshwater hatchetfishes of the characiform family Gasteropelecidae, suggesting that the morphological adaptations of G. branisai can be related, at least in part, to a similar lifestyle.     

广西宁明盆地第三纪鱼类化石生物地层

1宁明盆地的研究历史概况 宁明盆地位于广西西南部,十万大山西北坡,在中国第三系地层区划上属岭南地层区右江地层分区(李云通等,1984)。这是一个由NWW向张扭性断裂和NEE向压扭性断裂控制所形成的近东西向长菱形盆地(李嵘等,1995),其上发育着一套称为邕宁群的第三纪沉积,厚度较大,以砂岩、泥岩夹砂岩为主,角度不整合于侏罗系之上,含有鱼类、植物和孢粉等化石。     

Molecular analysis of ependymins from the cerebrospinal fluid of the orders clupeiformes and salmoniformes: no indication for the existence of an euteleost infradivision

Summary Ependymins represent the predominant protein constituents in the cerebrospinal fluid of many teleost fish and they are synthesized in meningeal fibroblasts. Here, we present the ependymin sequences from the herring (Clupea harengus) and the pike (Esox lucius). A comparison of ependymin homologous sequences from three different orders of teleost fish (Salmoniformes, Cypriniformes, and Clupeiformes) revealed the highest similarity between Clupeiformes and Cypriniformes. This result is unexpected because it does not reflect current systematics, in which Clupeiformes belong to a separate infradivision (Clupeomorpha) than Salmoniformes and Cypriniformes (Euteleostei). Furthermore, in Salmoniformes the evolutionary rate of ependymins seems to be accelerated mainly on the protein level. However, considering these inconstant rates, neither neighbor joining trees nor DNA parsimony methods gave any indication that a separate euteleost infradivision exists.     

Complement system of bony and cartilaginous fish

Accumulating evidence indicates that the complement system experienced a discontinuous development at an early stage of vertebrate evolution. Invertebrates such as echinoderms and ascidians, and the most primitive extant vertebrates, the cyclostomes, seem to have a primitive complement system equipped only with the alternative and lectin pathways. In contrast, cartilaginous fish and higher vertebrates seem to have a modern complement system which has two additional pathways, namely the classical and lytic pathways. Recent molecular analyses of the complement system of bony and cartilaginous fish have not only confirmed the above conclusion, but also revealed a unique characteristic of the complement system of fish, where certain key component genes are duplicated. The complement system seems to play a more pivotal role in body defence in fish, whose adaptive immunity is considered to be at a relatively undeveloped state.     

Primitive bony fishes, with especial reference to Cheirolepis and palaeonisciform actinopterygians

The relationships of the Devonian palaeonisciform fish Cheirolepis are examined and the early evolutionary trends within the Actinopterygii and the Osteichthyes are considered.
Cheirolepis is the most primitive known actinopterygian. The contemporary stegotrachelid palaeonisciforms are more advanced in their cranial and locomotor anatomy. The general directions of these advances are similar to those subsequently displayed by later palaeonisciforms over the stegotrachelids themselves. Cheirolepis , furthermore, possesses many characters which can be logically interpreted as primitive for the Osteichthyes by extrapolation of trends in actinopterygian and sarcopterygian lineages. 11 is the most primitive known osteichthyan.
The Osteichthyes are considered to have arisen from a micromerically-scaled acanthodian or acanthodian-like ancestor at the end of the Silurian period.     

Phosphoglucose isomerase isozymes in teleostean fishes from the Arabian Gulf

Two phosphoglucose isomerases (PGI) with different electrophoretic mobilities have been found in all groups of teleostean fishes studied, with the exception of the Clupeomorpha. PGI proved to be a good taxonomic criterion to differentiate members of the Nemipteridae, Sciaenidae, Platycephalidae and Stromateidae from the other teleost families.     

Respiratory Gas Bladders in Teleosts: Functional Conservatism and Morphological Diversity

SYNOPSIS. Respiratory gas bladders are found in the Osteoglossomorpha,Elopomorpha and Euteleostei and are absent in the Clupeomorpha.All teleosts with respiratory gas bladders share a common patternof air ventilation: during the transfer phase gas is transferredpassively from the gas bladder to the buccal cavity. Subsequently,gas is expelled during the active expulsion phase mediated byaction of the geniohyoideus muscle causing a positive pressurepulse in the buccal cavity. This is followed by an active intakephase by action of the sternohyoideus muscle creating a negativepressure pulse, which is succeeded by an extensive compressivephase by action of the geniohyoideus muscle forcing fresh airinto the gas bladder. Saltatory evolution of gas bladders andtheir buccal pumps seems to have proceeded by major transformationsin structural design without appreciable changes in the patternof neural control. The hypothesis of symmorphosis in gas bladderdesign is well corroborated by the independent evolution ofaccessory esophageal pumps in three unrelated lineages. Evolutionaryreversals (Primitive lung evolving into nonrespiratory hydrostaticswim bladder which subsequently reverts back to become a respiratorygas bladder) have occurred repeatedly. Such reversed shiftsare facilitated by the conserved neuromuscular pattern duringfunctional transformations. Experimental comparative evidenceis offered for the notion that evolutionary innovations mayinvolve the addition of entirely new functions (respiratory)of a structural complex (gas bladder) while the original functions(hydrostatic, hearing and sound production) are rigidly retained.The paucity in Elopomorpha and absence in Clupeomorpha of respiratorygas bladders reflect the lack of functional demands for newhabits in the environment rather than the absence of essentialpreexisting building blocks.     

Taxic and morphological diversification during the early radiation of Clupeomorpha (Actinopterygii,Teleostei)

Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of Earth's history. Here, we employed the superorder Clupeomorpha at the Early–Late Cretaceous boundary as a study case to investigate radiation types and their interactions, using both taxic and morphological approaches. Clupeomorpha is an extensively studied, diverse and ancient teleostean superorder with wide geographical and ecological distributions. We propose a model for calculating rates of origination in order to analyse the taxic diversification and employ geometric morphometrics to analyse the morphological diversification that occurred at the temporal boundary. The results suggest the absence of taxic radiation due to a constant increase in taxon origination. However, the expansion of the phylomorphospace occupation and the disparity increase suggest the presence of a ‘climatic–geographical’ or ‘broad diversification-like’ disparity, according to current classifications. This illustrates the incompatibility of current radiation classifications with this case study.     

Phylogenetic relationships of elopomorph fishes inferred from mitochondrial ribosomal DNA sequences

The superorder Elopomorpha, a grouping which includes all teleost fishes that possess a specialized leptocephalous larva [true eels (Anguilliformes), gulpers and bobtail snipe eels (Saccopharyngiformes), bonefishes, spiny eels, and halosaurs (Albuliformes, including Notacanthiformes), ladyfishes and tarpons (Elopiformes, including Megalopiformes)] comprises >800 species for which phylogenetic relationships are poorly understood. In the present study, we analyzed mitochondrial DNA sequences in segments of the 12S and 16S rRNA genes in 33 elopomorph taxa encompassing all of the previously proposed orders, and 9 of the 15 currently recognized families of the Anguilliformes, as well as outgroup representatives from the superorders Osteoglossomorpha (nine species) and Clupeomorpha (three species), to develop phylogenetic hypotheses based on distance and parsimony methods. Both methods failed to support the monophyly of the Elopomorpha, casting doubt on the validity of the leptocephalus as an elopomorph synapomorphy. The orders Elopiformes, Albuliformes, and Anguilliformes, however, were resolved as monophyletic assemblages. Parsimony analysis supported the separation of the Anguilliformes into two groups (primitive and advanced) based on the presence of divided versus fused frontal bones. In addition, the molecular data indicated a close affinity of the anguilliform Thalassenchelys coheni (incertae sedis), known only from the leptocephalus, with the family Serrivomeridae. The implications of these data as regards the evolution of the elopomorph assemblage are discussed.     

The pectoral anatomy of selected Ostariophysi. I. The Characiniformes.

The muscles and bones of the pectoral fin of Serrasalmus nattereri, the piranha, resemble those of generalized, lower teleosts with specializations related to a body shape adapted for high-speed carnivory; the pectoral fins being highly mobile with strong ligaments to the rays. The presence of two occipital nerves appears primitive, while the emergence of the subclavian artery within the branchial cavity, as in Gasteropelecus sternicla, appears specialized. The muscles and bones of the latter fish, a fresh-water flying fish, are specialized for self-propelled, aerial flight in the fusion of the right and left girdles greatly expanded for insertions of complex appendicular (flight) muscles, and in the consolidation of the rays and radials into one functional unit moving vertically in flight through contraction of vertical, massive ventral flight muscles. The bony pectoral anatomy of Electrophorus electricus, the electric eel, is specialized in having a mobile joint between the primary girdle and the cleithrum, the former being suspended vertically from the cleithrum by ligaments. The proximal radials and rays are very numerous and vertically aligned. The cleithrum is shaped to accommodate the extensive sternohyoid and pharyngocleithral muscles. The sheet-like appendicular muscles extend beyond the special joint and control its movement. The deeper muscles do not cross this joint. The arterial system is specialized in lacking a deep brachial artery.     

贵州兴义发现最原始弓鳍鱼

记述在贵州兴义著名的贵州龙化石层（上三叠统卡尼介）中发现的最原始弓鳍鱼而建立了一新属新种－优美贵州弓鳍鱼（Guizhouamia bellula gen.et sp.nov.)。     

Bile salts of fishes collected on the Zaire River Expedition (1974-5): their chemical nature and its possible significance

Bile salts from 21 fish species caught during the Zaïre River Expedition (1974–5) have received partial or complete chemical analysis. Conclusions from the results are as follow. (1) Polypterus bile salts are biochemically advanced, but with easily detectable features regarded as relicts from ancestral stock. The bile acids include haemulcholic acid, previously found only in a marine teleost and an unidentified acid also found in a mormyrid. (2) This mormyrid has advanced bile salts, consisting almost entirely of taurine conjugates of haemulcholic acid (present in Polypterus) , and two other C₂₄ acids. (3) Three Alestes and three Distichodus species have no more than traces of primitive bile salts; their bile acids suggest a degree of activity of intestinal microorganisms during the enterohepatic circulation not previously noticed in fishes. (4) The predatory Hydrocynus has bile acids of an omnivorous rather than a carnivorous type. (5) The Barbus species have primitive bile salts closely similar to those of Cyprinidae previously examined but containing also (in two species) a newly-discovered bile alcohol sulphate: in contrast, a Varicorhinus does not have this new substance and has a chief bile salt found so far only as a minor constituent in the Cyprinidae. (6) Two Labeo species are different from all other cyprinids examined: diey both have a new major bile alcohol sulphate. (7) Four Siluriformes show evidence of enterohepatic changes that might be characteristic of some tropical freshwater fish; three have taurine-conjugated haemulcholic acid. (8) Synodontis species are remarkable in having a high proportion of unconjugated bile acid ions and this finding was confirmed with fresh material.     

Mutant Medaka fish having a deficiency in otolith-vestibular system and their behavior in microgravity

Vestibular and visual senses are two major factors fish use for controlling their posture under 1 G conditions. From various studies in the past (parabolic flights and some ground-laboratory experiments), I came to have a hypothesis that "heavily eye-dependent" fish are tolerant to microgravity (micro-G). Theoretically, for "heavily eye-dependent" fish, the following three types may exist. (a) Fish having good eyesight, and having an ordinary sensitivity to gravity, (b) Fish having an ordinary eyesight, and having less sensitivity to gravity, (c) Fish having good eyesight, and having less sensitivity to gravity. In Medaka fish (Oryzias latipes), these three types have successfully been obtained. In this paper, the behavior of such different types of Medaka fish under micro-G will be studied by use of parabolic flights of an airplane. The ground-laboratory experiments are also reported, which focus on the contribution of both vestibular and visual senses to the posture control for each of three types of Medaka fish.     

First discovery of a primitive coelacanth fin fills a major gap in the evolution of lobed fins and limbs

The fossil record provides unique clues about the primitive pattern of lobed fins, the precursors of digit-bearing limbs. Such information is vital for understanding the evolutionary transition from fish fins to tetrapod limbs, and it guides the choice of model systems for investigating the developmental changes underpinning this event. However, the evolutionary preconditions for tetrapod limbs remain unclear. This uncertainty arises from an outstanding gap in our knowledge of early lobed fins: there are no fossil data that record primitive pectoral fin conditions in coelacanths, one of the three major groups of sarcopterygian (lobe-finned) fishes. A new fossil from the Middle-Late Devonian of Wyoming preserves the first and only example of a primitive coelacanth pectoral fin endoskeleton. The strongly asymmetrical skeleton of this fin corroborates the hypothesis that this is the primitive sarcopterygian pattern, and that this pattern persisted in the closest fish-like relatives of land vertebrates. The new material reveals the specializations of paired fins in the modern coelacanth, as well as in living lungfishes. Consequently, the context in which these might be used to investigate evolutionary and developmental relationships between vertebrate fins and limbs is changed. Our data suggest that primitive actinopterygians, rather than living sarcopterygian fishes and their derived appendages, are the most informative comparators for developmental studies seeking to understand the origin of tetrapod limbs.     

A primitive anomodont therapsid from the base of the Beaufort Group (Upper Permian) of South Africa

Patranomodon nyaphulii , known from a nearly complete skull, lower jaw and partial postcranial skeleton, is morphologically the most primitive anomodont therapsid yet discovered. It is from the Eodicynodon Assemblage Zone, the lowest biozone of the Beaufort Group of South Africa, which has a primitive therapsid fauna comparable with that of the Russian Zone I. Patranaomodon is primitive with respect to other anomodonts in having short palatal exposure of the premaxilla, an unreduced tabular, a slit-like interpterygoidal vacuity, a screw-shaped jaw articulation (which precludes fore-aft sliding of the lower jaw), and only three sacral vertebrae. The poorly-known Galechirus and Galepus from the younger Cistecephalus Assemblage Zone appear to be at a comparably primitive evolutionary grade, and the three genera are tentatively united in the family Galechiridae. The taxon Dromasauria is shown to be paraphyletic and therefore should be discarded.     

Occurrence of biflagellate spermatozoa in Cetopsidae, Aspredinidae, and Nematogenyidae (Teleostei: Ostariophysi: Siluriformes)

In the present study spermiogenesis was investigated in Cetopsis coecutiens (Cetopsidae), and Bunocephalus amazonicus (Aspredinidae), while spermatozoa ultrastructure was investigated in C. coecutiens, B. amazonicus, and Nematogenys inermis (Nematogenyidae). Aspredinidae and Cetopsidae share a spermatogenesis of the semicystic type, and a particular type of spermiogenesis process not reported in any fish group. In the three species analyzed, spermatozoa are biflagellate with flagella having the classical axoneme formulae (9 + 2). The analysis of thirteen characters showed the presence of eight characters shared by Cetopsidae and Aspredinidae, and six characters shared by Cetopsidae and Nematogenyidae, which may suggest that these three families may be more related than actually hypothesized, comprising a very primitive siluriform lineage originated after Diplomystidae.     

Serotonin-like immunoreactive cells in the pulmonary epithelium of ancient fish species

The pulmonary mucosa of three species of ancient fish was studied immunohistochemically to show the distribution of serotonin, regarded as the main monoamine of mammalian bronchopulmonary paraneurons. Serotonin-like immunoreactive cells, dispersed through the airway epithelium as single cells, were found in all the fish species studied. They are presumably equivalent to the neuroendocrine cells reported in the lungs of mammalian and submammalian vertebrates. However, the precise role and the function of these cells remain unknown. Since the species studied belong to the most primitive extant groups of ancient fish, the present investigation suggests that serotonin is widely distributed in the lungs of the vertebrates. Several peptides, known to be specific cytochemical markers for the identification of the pulmonary neuroendocrine cells of mammals, are being investigated in the lungs of the fish species studied. They may help to trace the phylogeny of the pulmonary neuroendocrine cell system and to elucidate its function in lower vertebrates.