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Belone is distinguished from other genera of Belonidae mostly because of its complete cephalic sensory system, presence of gill rakers, vomerine teeth, and the pattern of its dentition. This eastern North Atlantic genus contains two extant species and at least three described fossil species from Lower Oligocene and Upper Miocene formations in Europe. †Belone countermani, sp. nov., a new species of needlefish from the Tortonian Upper Miocene St. Marys Formation of Calvert Cliffs (Maryland, U.S.A.), is described herein based on a well-preserved three-dimensional associated pair of upper and lower jaws. This rostrum represents the only record of this genus in the western North Atlantic Ocean. †Belone countermani is characterized by a unique dental pattern on the dentary. The dentary commissural region is filled with several rows of small accessory teeth (five to seven) that gradually decrease in number of rows; along the symphysial region there is one inner row of conical teeth and one external row ...

Validity of the largest size accounts is not well documented and most published accounts of body colora- tion describe dead specimens lacking scales instead of the color of freshly caught opah. Maximum length is at least 163 cm fork length and maximum weight about 89 kg. The body color of fresh specimens is vermilion with white spots.

Dissection and histological analyses revealed the swimbladder of Hemiramphus far and H. robustus to comprise a matrix of discrete, gas-filled vesicles of 1–6 mm in diameter. The vesicles are not richly vascular and no discrete capillary bed organs were found. The anterior and posterior ends of the swimbladder have asymmetric projections that extend rostrad and caudad, respectively. These projections and some surrounding fatty tissue contain what we term protovesicles, which have thick walls that we infer expand to become the thin-walled vesicles of the main vesicular swimbladder. Dissection of museum specimens of other species of Hemiramphus and Oxyporhamphus convexus confirmed the presence of a vesicular swimbladder. However, examination of museum specimens of other hemiramphids, including O. micropterus, and flyingfishes revealed only a simple sac-like swimbladder. Presence of this unusual swimbladder in two genera within the same family is indicative of a strong synapomorphy that, in conjuncti...

We have previously documented multiple, independent origins of placentas in the fish family Poeciliidae. Here we summarize similar analyses of fishes in the family Zenarchopteridae. This family includes three live-bearing genera. Earlier studies documented the presence of superfetation, or the ability to carry multiple litters of young in different stages of development in the same ovary, in some species in all three genera. There is also one earlier report of matrotrophy, or extensive postfertilization maternal provisioning, in two of these genera. We present detailed life-history data for approximately half of the species in all three genera and combine them with the best available phylogeny to make inferences about the pattern of life-history evolution within this family. Three species of Hemirhamphodon have superfetation but lack matrotrophy. Most species in Nomorhamphus and Dermogenys either lack superfetation and matrotrophy or have both superfetation and matrotrophy. Our phylogenetic analysis shows that matrotrophy may have evolved independently in each genus. In Dermogenys, matrotrophic species produce fewer, larger offspring than nonmatrotrophic species. In Nomorhamphus; matrotrophic species instead produce more and smaller offspring than lecithotrophic species. However, the matrotrophic species in both genera have significantly smaller masses of reproductive tissue relative to their body sizes. All aspects of these results are duplicated in the fish family Poeciliidae. We discuss the possible adaptive significance of matrotrophy in the light of these new results. The two families together present a remarkable opportunity to study the evolution of a complex trait because they contain multiple, independent origins of the trait that often include close relatives that vary in either the presence or absence of the matrotrophy or in the degree to which matrotrophy is developed. These are the raw materials that are required for either an analysis of the adaptive significance of the trait or for studies of the genetic mechanisms that underlie the evolution of the trait.

To investigate jaw evolution in beloniform fishes, we reconstructed the phylogeny of 54 species using fragments of two nuclear (RAG2 and Tmo-4C4) and two mitochondrial (cytochrome b and 16S rRNA) genes. Our total molecular evidence topology refutes the monophyly of needlefishes (Belonidae) and halfbeaks (Hemiramphidae), but supports the monophyly of flyingfishes (Exocoetidae) and sauries (Scomberesocidae). Flyingfishes are nested within halfbeaks, and sauries are nested within needlefishes. Optimization of jaw characters on the tree reveals a diverse array of evolutionary changes in ontogeny. During their development, needlefishes pass through a "halfbeak" stage that closely resembles the adult condition in the hemiramphid halfbeaks. The reconstruction of jaw transitions falsifies the hypothesis that halfbeaks are paedomorphic derivatives of needlefishes. Instead, halfbeaks make up a basal paraphyletic grade within beloniforms, and the needlefish jaw morphology is relatively derived. The parallel between needlefish ontogeny and beloniform phylogeny is discussed, and clades amenable to future morphological analysis are proposed.

Spinoid scales appear early in the development of Swordfish, Xiphias gladius, and are first discernable in the larval stage. Scales vary in form between two principal types: small single and multispined scales and large multispined scales. Unlike the typical teleostean condition, Xiphias scales are attached along their base, not at their proximal end within scale pockets. Scales persist in juveniles and adults, that is, scales are not shed or resorbed. Scales become more deeply embedded within the dermis as the dermis thickens in ontogeny; consequently only the tips of spines protrude through the dermis of adults. A network of mucous canals with regularly spaced pores to the exterior develop in the dermis of adults, and the mucus produced further insulates scales from the surface of the integument. The ontogeny of the squamation of Xiphias differs from that of the related Istiophoridae.

Sequence variation in the mitochondrialCytochrome b (Cytb) gene was assayed infour of six extant Bermuda killifishpopulations, representing two endemic species,to test taxonomic and phylogenetic hypothesesand reconstruct colonization history. Twodivergent (4.6%) haplotypes were detected; oneis identical to the Georgia 2c haplotype ofF. heteroclitus and is fixed in threeeastern populations: Lover's Lake (F.relictus), Mangrove Lake (F. bermudae),and Walsingham Pond. The second is fixed andrestricted to a western population, Evan'sPond. Likelihood and parsimony cytochrome btrees recognize a Bermuda Fundulus / F. heteroclitus clade in which the Evan's Pondhaplotype is basal. Phylogenies and haplotypedivergence indicate at least two Bermudacolonizations, the more recent involvingtransfer of the Georgia 2c haplotype. Enforcing Bermuda killifish monophyly, aspredicted from a single colonization event,does not increase tree length significantly;i.e., the trees also are consistent with asingle colonization. However, divergencebetween the Evan's Pond haplotype and the F. bermudae / F. relictus / Georgia 2chaplotype (4.6%) far exceeds the maximumdivergence among all F. heteroclitus,F. bermudae, and F. heteroclitushaplotypes (1.2%) and argues for independentcolonizations. Alternatively, recentintroduction of F. heteroclitus couldaccount for occurrence of the GA2c haplotype inBermuda but does not explain the presence ofthe genetically divergent Evans' Pondhaplotype. Cytb sequences areuninformative of the taxonomic status ofBermuda endemics, F. bermudae and F.relictus, but support recognition of theEvan's Pond population as an evolutionarilysignificant unit within the F. heteroclitus group.

Fishing can change the biological diversity of an ecosystem substantially, and determining the effects of fishing on marine biodiversity requires a variety of data, chief among them the proper identification of organisms. Because identification of all organisms in an ecosystem is not currently possible, target taxonomic groups (taxa) must be selected. The current status of taxonomic information varies greatly among taxa and among geographic areas within taxa. Problems include nomenclature, diagnoses, and determination of taxonomic relationships. We provide examples of a variety of these problems. We then propose a series of criteria for evaluating available taxonomic information in determining the potential reliability of species identification, including recency and comprehensiveness of revisionary studies, methods used for systematic and phylogenetic studies, adequacy of documentation, and evidence of peer review. When the goal is to explore biodiversity, these criteria must be used differently from when measuring and monitoring biodiversity.

The jaw morphology of needlefishes (Beloniformes : Belonidae) passes through distinctive ontogenetic stages. When hatched, larvae have short jaws of equal length. The lower jaw first elongates to produce a halfbeak form, then the upper jaw elongates to produce the adult needlenose morphology. Onset and duration of the halfbeak stage vary among belonid species. We tested the hypothesis that heterochronic evolution produced this diversity in jaw morphology

The first standardized, global assessment of these fishes, using Red List criteria, reveals threatened species needing protection.

The structure, origin, and spread of the family Percidae are reviewed briefly, and its characteristics compared with those of other families of freshwater fishes. It is suggested that the percids, essentially riverine, have been restricted in their success in North America by the presence of the Centrachidae. Percids are defined as temperate mesothermal fish, and this physiological characteristic together with osmoregulatory capacity and swimming performance is shown to limit the ranges of the perches. The degree of development of the tapetum lucidum in Stizostedion spp. and of the lateral line in all percids is related to differences in pattern of development, feeding behavior, and habitat. Reproductive, feeding and migratory behaviour are also reviewed. Key words: Percidae, structure, origin, biology, morphology, systematics, migration

Two phyletic lines are present in the Percidae: the Percinae, in which the anteriormost interhaemal bone is much larger than the posterior ones and the anal spines usually are well developed, and the Luciopercinae, in which the interhaemal bones are of uniform size and the anal spines are poorly developed. Parallel evolution has produced in each subfamily small, benthic, rheophilic forms with depressed or terete bodies and reduced or vestigial swimbladders. This differentiation is shown by dividing each subfamily into two tribes. Within the Percinae, the Etheostomatini (Percina, Ammocrypta, and Etheostoma) are interpreted as derivatives of the Percini (Perca, Gymnocephalus [=Acerina], and Percarina). The North American species Perca flavescens is distinguished from the Eurasian species P. fluviatilis and P. schrenki on the basis of the more posterior position of the predorsal bone. In the Luciopercinae, the Romanichthyini (Zingel [=Aspro] and Romanichthys) have evolved from the Luciopercini (Stizostedion [including Lucioperca]). Key words: Percidae, systematics, zoogeography, evolution

S. munroi, sp. nov.. is described from northern Australia and southern Papua New Guinea. It has been confused with S. niphonius of the north-western Pacific because both are spotted species with many (19-22) dorsal spines. S. niphonius is unique among the 18 species of the genus in having a straight intestine; S. munroi, like most other species of Scomberomorus, has two loops and three limbs to the intestine. S. munroi has more vertebrae (50-52) than S. niphonius (48-50) and most other species of Australian Scomberomorus (S. commerson 42-46, S. queenslandicus 48-49, S. semifasciatus 44-46), except for S. multiradiatus from Papua New Guinea (55-56). S. munroi has a deeper body and a longer postorbital distance than S. niphonius.