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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...

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.

The New World clade of needlefishes (Belonidae) includes species distributed along the Pacific and Atlantic coasts of the Americas and in freshwater basins of Central and South America. Phylogenetic relationships among 13 species of the group were assessed based on data from two nuclear genes (RAG2 and Tmo-4C4), two mitochondrial genes (cytochrome b and 16S rRNA), and a small suite of morphological characters. In general, there was concordance between separate analyses of nuclear and mitochondrial characters, and RAG2 was found to be a particularly useful gene for phylogeny reconstruction. Morphology supported an alternative phylogenetic pattern, but this was probably a result of the small number of characters and the lack of a thorough anatomical survey. The total evidence hypothesis divides the group into two major clades. In one, Pseudotylosurus from freshwater in South America is most closely related to a pair of Strongylura species from the western and eastern Atlantic; in the other, Potamor...

species group was fully supported, with the eastern Atlantic S. tritor basal to the New World taxa as predicted from the eastern Atlantic/eastern Pacific generalized biogeographic track. Surprisingly, no differences were observed between the mitochondrial genomes of S. regalis and S. maculatus. However nuclear DNA and morphological characters confirm the species status of these two taxa, leading us to posit the introgressive loss of the S. maculatus mtDNA genome following hybridization with S. regalis. Chronological estimates were applied to the phylogenetic topology combining geologic dates for putative vicariant events with molecular distance values. These estimates indicate a pre-isthmian divergence for the western Atlantic S. maculatus, followed by divergence of the common ancestors of the western Atlantic (S. brasiliensis and S. regalis) and eastern Pacific (S. concolor and S. sierra) species resulting from the rise of the Isthmus of Panama and closure of associated seaways.

With the new ocean regime coming into being, many of the countries including India have declared an EEZ (Exclusive Economic Zone) which extends national jurisdiction to 200 miles from the coast. This has created a greater awareness of our responsibility to wards the judicious exploitation of the living and non living resources coming under the extended jurisdiction. The problems of survey, assessment, utilization and management of the resources thus assumes priority. At the same time, the management of living resources, particularly the fishery resources receive both national and international importance. This is all the more so, as the exploitation of living resources has hitherto been confined to a narrow belt of the neritic waters. In the marine fisheries sector, with a decade of stagnation in world fish production, the declaration of the EEZ has given high hopes to some nations of substantially aug menting their fish production. To countries which had well established distant waterfishing operations covering the EEZ of other countries, the continuation of such operations poses serious problems. The new ocean regime undoubtedly offers some of the developing coun tries an opportunity for developing and expanding their capabilities of harvesting fish from their EEZ through their own effort or through collaborative ventures.

In 1979 at the request of the Comision Permanente del Pacifico Sur, staff members of the Inter-American Tropical Tuna Commission prepared synopses of eight species of scombrid fishes. These are to be published in Spanish in Revista de la Comision Permanente del Pacifico Sur, number 11, in 1980. This volume contains English versions of those synopses. The Spanish and English versions are not identical, however, the latter having been updated and somewhat modified after the Spanish versions were submitted for publication. These synopses follow closely the format prepared by Rosa (1965) for the synopses to be published by the Food and Agriculture Organization of the United Nations and cooperating organizations. However, instead of preparing detailed taxonomic reviews of the individual species, the taxonomic information for all of the scombrids and billfishes has been put into a separate chapter.

Zenarchopterus robertsi n. sp. is described from Ovi Creek, a high-gradient tributary of the Kumusi River which drains northeast into the Solomon Sea, Z. alleni n. sp. from a single male taken in the Mamberamo River in Irian Jaya. Both species differ from all other described species of Zenarchopterus in having the fifth and sixth anal rays of the male greatly elongate. Most other species have the sixth or the sixth and seventh rays variously modified. The other two freshwater species of Zenarchopterus known from New Guinea, Z. kampeni (found in the Sepik, Ramu and Mamberamo rivers which drain north) and Z. novaeguineae (found in at least three south-draining rivers, the Lorentz, Fly and Laloki) have the sixth anal ray of males expanded and paddle-shaped. The two new species have more predorsal scales (47-53 in Z. robertsi, 66 in Z. alleni) than do other species of the genus and the predorsal scales are not enlarged but about the same size as adjacent scales. Both new species have many vertebrae, usually 47 or 48 in Z. robertsi, 49 in Z. alleni. They differ in upper jaw length, the upper jaw being longer than wide in Z. alleni, length about equal to width in Z. robertsi. The pectoral fin is much longer than head length in Z. alleni, equal to or shorter than head length in all other species of the genus. There are at least 34 nominal species of Zenarchopterus of which about 17 appear to be valid. Biological notes are included on Z. robertsi. Geographic variation is discussed in Z. novaeguineae. The type-specimens of both Z. kampeni and Z. sepikensis came from the Sepik River and represent the same species, the former being the valid name.

83b. Shark ageing methods and age estiation of scalloped hammerhead, Sphyrna lewini, d dusky, Carc arhinus obscurus, sharks based on ertebral ring counts. NOAA Tech. Rep. NMFS of the spurdog (Squalus acanthias) using tetracycline.J. Mar. Biol. Assoc. U.K. 65:641-651. URIST, M. R., AND K. H. IBSEN. 1963. Chemical reactivity of mineralized tissue with oxytetracycline. Arch. Pathol. 76:484-496.

Two phyletic lines are recognized within 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, bottom-dwelling 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). In the Luciopercinae, the Romanichthyini (Zingel [= Aspro] and Romanichthys) have evolved from the Luciopercini (Stizostedion [including Lucioperca]). A table of vertebral numbers is given.

The number of nominal species and subspecies described per year are compared with the cumulative summary of the number of forms considered valid. The history of darter descriptions is divided into four periods: "Beginnings" (1818-1840); "Golden Era" (1841-1892); "Doldrums" (1893-1931); and "Reawakening" (1932-present). The success of different ichthyologists in describing valid taxa is assessed. The number of specimens per type-series forms a strongly skewed distribution from 42 species based on only the holotype to the 1338 type-specimens of Boleosoma nigrum eulepis. The 25 repositories of the 4863 type-specimens of 185 nominal species of darters are divided into three groups based on the number of primary and secondary types. The present number of valid species and subspecies (139) is predicted to rise to about 160 by the year 2000.

University of California Riverside Soils Department and Agricultural Extension Service for their respective services in soil and water analysis. Research facilities used in these studies were partly financed by U. S. Public Health Service Grant E-4107 (Aquatic midge investigations in southern California). This paper is No. 1706, University of California Citrus Research Center and Agricultural Experiment Station, Riverside, California.