Lynne R. Parenti

Evolution and Phylogeny of Gonad Morphology in Bony Fishes

Abstract Gonad morphology at the gross anatomical or histological levels has long been studied by fisheries biologists to identify annual reproductive cycles and length of breeding season, among other goals. Comparative surveys across vertebrate taxa have not been detailed enough, however, to describe fully the differences and similarities among gonads of bony fishes and other vertebrates, and to use gonad morphology in phylogenetic systematic analyses. An emerging constant among vertebrates is the presence of a germinal epithelium composed of somatic and germ cells in both males and females. In females, the germinal epithelium lines the ovarian lamellae. In males, arrangement of the germinal epithelium into compartments varies among osteichthyans: basal taxa have an anastomosing tubular testis, whereas derived taxa have a lobular testis. The lobular testis is proposed as a synapomorphy of the Neoteleostei. The annual reproductive cycle is hypothesized to be the source of morphological variation among testis types. Elongation of germinal compartments during early maturation may result in a transition from anastomosing tubular to lobular testes. In all male atherinomorphs surveyed, spermatogonia are restricted to the distal termini of lobules rather than being distributed along the lobule; there is an epithelioid arrangement of Sertoli and germ cells rather than a germinal epithelium. Arrest of the maturation-regression phases is hypothesized to lead to formation of the atherinomorph testis. Atherinomorphs also have a distinctive egg with fluid, rather than granular, yolk. Variation among germinal epithelia is interpreted in a developing phylogenetic framework to understand evolution of gonad morphology and to propose gonad characters for phylogenetic analyses.

Taxonomic Impediment or Impediment to Taxonomy? A Commentary on Systematics and the Cybertaxonomic-Automation Paradigm

Marcelo R. de Carvalho AE Flavio A. Bockmann AE Dalton S. Amorim AE Carlos Roberto F. Brandao AE Mario de Vivo AE Jose L. de Figueiredo AE Heraldo A. Britski AE Mario C. C. de Pinna AE Naercio A. Menezes AE Fernando P. L. Marques AE Nelson Papavero AE Eliana M. Cancello AE Jorge V. Crisci AE John D. McEachran AE Robert C. Schelly AE John G. Lundberg AE Anthony C. Gill AE Ralf Britz AE Quentin D. Wheeler AE Melanie L. J. Stiassny AE Lynne R. Parenti AE Larry M. Page AE Ward C. Wheeler AE Julian Faivovich AE Richard P. Vari AE Lance Grande AE Chris J. Humphries AE Rob DeSalle AE Malte C. Ebach AE Gareth J. Nelson

Pharyngeal jaw morphology and homology in Sicydiine Gobies (Teleostei: Gobiidae) and allies

An extremely large number of fifth ceratobranchial teeth, with highly modified, striated, and hooked tips were observed in the central and western Pacific sicydiine goby genus Stiphodon.A scanning electron microscopic study of the form and arrangement of fifth ceratobranchial teeth was conducted to assess the distribution of these modifications in sicydiine gobies and their putative close relatives. Our goals were to explore a new set of characters in gobioid systematics, to test sicydiine monophyly, and to test hypotheses of relationships of sicydiine gobies. Sicydiines are hypothesized herein to be most closely related to the western Pacific Tukugobius and Rhinogobius,freshwater genera with which they share thickened pelvic‐fin rays, no teeth on the anterior portion of the fifth ceratobranchial bones, fifth ceratobranchial teeth with differentiated and striated tips, and overlapping anterior rami of the fifth ceratobranchial bones. The latter two characters occur in some, but not all, sicydiines. The pantropical freshwater goby Awaous,often classified with sicydiines, is not considered the closest relative of the subfamily. The highly modified fifth ceratobranchials of Stiphodon are similar to, and concluded here to be homoplasious with, those of the mudflat‐dwelling New World goby Evorthodus and the Indo‐west Pacific oxudercine gobies, represented in this study by Pseudapocryptes. J. Morphol. 237:257–274, 1998. Published 1998 Wiley‐Liss, Inc.

Mitigating the impact of oil‐palm monoculture on freshwater fishes in Southeast Asia

Anthropogenic land-cover change is driving biodiversity loss worldwide. At the epicenter of this crisis lies Southeast Asia, where biodiversity-rich forests are being converted to oil-palm monocultures. As demand for palm oil increases, there is an urgent need to find strategies that maintain biodiversity in plantations. Previous studies found that retaining forest patches within plantations benefited some terrestrial taxa but not others. However, no study has focused on aquatic taxa such as fishes, despite their importance to human well-being. We assessed the efficacy of forested riparian reserves in conserving freshwater fish biodiversity in oil-palm monoculture by sampling stream fish communities in an oil-palm plantation in Central Kalimantan, Indonesia. Forested riparian reserves maintained preconversion local fish species richness and functional diversity. In contrast, local and total species richness, biomass, and functional diversity declined markedly in streams without riparian reserves. Mechanistically, riparian reserves appeared to increase local species richness by increasing leaf litter cover and maintaining coarse substrate. The loss of fishes specializing in leaf litter and coarse substrate decreased functional diversity and altered community composition in oil-palm plantation streams that lacked riparian reserves. Thus, a land-sharing strategy that incorporates the retention of forested riparian reserves may maintain the ecological integrity of fish communities in oil-palm plantations. We urge policy makers and growers to make retention of riparian reserves in oil-palm plantations standard practice, and we encourage palm-oil purchasers to source only palm oil from plantations that employ this practice.

Reproductive biology and systematics of phallostethid fishes as revealed by gonad structure

Testis and ovary structure was examined histologically in seven of the 19 species in the three tribes of the teleost fish family Phallostethidae, series Atherinomorpha. These diminutive species have testes in which spermatogonia are restricted to the distal ends of lobules, a diagnostic character of atherinomorphs. Sperm in the ovarian lumen and chorionic attachment filaments on eggs confirms observations that phallostethids are internally fertilizing and lay fertilized eggs. The immense number of sperm in ovarian cavities means that all, or nearly all, ovulated oocytes will be fertilized. As revealed in histological sections, testicular ducts in most phallostethids examined contain ‘granular’ secretions that have not been reported in any other atherinomorphs. Species in the tribes Neostethini and Gulaphallini form unique spermatozeugmata that differ from those of other internally fertilizing atherinomorphs examined in that they have sperm nuclei that are oriented towards one side of the sperm bundle. Spermatozeugmata are not formed in species in the tribe Phallostethini. A unique spermatozeugmatum is interpreted as being a diagnostic character of phallostethids that has been lost or modified in phallostethins. Gonads of phallostethids and hypothesized close relatives are posterior and posteroventral to the gut rather than dorsal to the gut, as they are in most other fishes. Museum specimens preserved over sixty-five years ago are as useful for demonstrating gonad histology as are those preserved in the past few years.

Adrianichthys roseni and Oryzias nebulosus, two new ricefishes (Atherinomorpha: Beloniformes: Adrianichthyidae) from Lake Poso, Sulawesi, Indonesia

Two new species of ricefishes or buntingi, Adrianichthys roseni and Oryzias nebulosus, are described from Lake Poso, Sulawesi Tengah, Indonesia, bringing to 12 the number of endemic ricefishes known from Sulawesi. Adrianichthys roseni and its sole congener, A. kruyti, are distinguished from other relatively large-bodied ricefishes, Xenopoecilus, in having orbits that project beyond the dorsal profile of the head; paired preethmoid cartilages (versus single or absent in Xenopoecilus); and 13–16 (versus 8–13) dorsal fin rays. Also, as in A. kruyti, the lower jaw of A. roseni is enclosed in the upper jaw when the mouth is closed; however, the upper jaw is not as large and broadly expanded as in A. kruyti. Adrianichthys roseni differs further from A. kruyti in having fewer scales in a lateral series (approximately 63–65 versus 70–75), attaining a smaller maximum recorded standard length (90 mm versus 109 mm), and having the lateral process of the pelvic bone in line with the fifth, rather than the eighth, pleural rib. Oryzias nebulosus shares with O. nigrimas, also from Lake Poso, a unique sexual dichromatism in preserved specimens: adult males are dark gray to black, whereas females are a lighter grayish-yellow to brown. Relative to O. nigrimas, O. nebulosus is a small species (maximum recorded SL 33 mm versus 51 mm), with pelvic fins relatively anterior (lateral process of pelvic bone is in line with the third, fourth, or fifth, modally fourth, rather than the fourth or fifth, modally fifth, pleural rib), dorsal fin relatively anterior (origin above the 12–14th anal fin ray as opposed to the 15–17th anal fin ray), precaudal vertebrae 11–13, modally 12 (versus 13–14, modally 13), and relatively straight, narrow and slender (as opposed to curved, broad, and robust) ossified and cartilaginous portions of the gill arches. Endemic buntingi are threatened by introduction of exotic species, overfishing, and pollution. A conservation plan includes rearing native fishes for local use as ornamental fishes and possible reintroduction.

Morphometric and meristic variation in ricefishes, genus Oryzias: A comparison with cytogenetic data.

Morphometric and meristic data from type and other material of ricefishes of the genusOryzias, particularly onO. latipes andO. curvinotus, were retaken to compare relationships of ricefishes indicated by morphological data with the relationships indicated by the cytogenetic analyses (Uwa, 1986). Along with morphometric and meristic characters traditionally used, two morphometric characters are useful for the classification of this genus: the relative length of the abdominal part and the relative position of the dorsal-fin origin. External anatomical data mostly agree with a classification of ricefishes based on karyology; although, like the cytogenetic data, they are not sufficient to distinguish all species, or to define monophyletic groups.Oryzias latipes is widespread in eastern Asia.Oryzias curvinotus, a name applied to ricefish from Hainan Island, is distributed more widely in southern China, including Hainan, Guangdong, Hong Kong, and Hanoi.

A New, Remarkably Colorful, Small Ricefish of the Genus Oryzias (Beloniformes, Adrianichthyidae) from Sulawesi, Indonesia

Abstract Oryzias woworae, a new species of ricefish, is described from a freshwater habitat on Muna Island off the southeastern coast of the main island of Sulawesi, Indonesia. The new species is distinguished from all other known ricefishes by a remarkable color pattern of both sexes in life: the ventral surface of head and body anterior to the pelvic fins, dorsal portion of pectoral fins, dorsal-fin base, posterior portion of anal-fin base, caudal peduncle, and dorsal and ventral portions of caudal fin are brilliant red; the midlateral scales from just posterior to the eye to the caudal-fin base and the body scales anterior to the anal fin and ventral to midlateral scales are steel blue; the blue coloration is most prominent in adult males. Oryzias woworae, the smallest known ricefish from Sulawesi, is hypothesized to be a member of an unnamed clade of ricefishes diagnosed by a truncate, rather than lunate or emarginate, caudal fin. Description of O. woworae brings the recognized number of species in the beloniform family Adrianichthyidae to 29, 13 of which are endemic to Sulawesi. Ricefishes, in particular the new species, may serve as icons to generate interest in conservation of the endemic freshwater biota of Sulawesi. Oryzias woworae, jenis baru ikan padi dideskripsi dari perairan Pulau Muna, perairan pantai Sulawesi Tenggara, Indonesia. Ikan jenis baru ini dapat dengan mudah dibedakan dari jenis yang telah dikenal sebelumnya, dari pola warnanya yang sangat menyolok. Ikan jantan maupun betina berwarna merah cerah dari kepala bagian bawah, tubuh depan bagian bawah sampai sirip perut, sirip dada bagian atas, pangkal sirip punggung, pangkal sirip anal bagian belakang, batang ekor, pangkal sirip ekor bagian atas dan bawah; warna biru terang dijumpai pada sisik tepat dibelakang mata, sisik pada pertengahan bagian tubuh sampai pangkal sirip ekor dan sisik didepan sirip anal dan sirip perut sampai sisik tengah tubuhnya; warna biru ini sangat jelas terlihat pada jantan dewasa. Oryzias woworae, jenis ikan padi terkecil dari Sulawesi diperkirakan merupakan anggota dari grup yang belum bernama, bercirikan sirip ekor yang bentuknya lebih cenderung bersegi dari pada bulan sabit ataupun agak cekung. Deskripsi Oryzias woworae menyebabkan jumlah species dari ordo Beloniformes, famili Adrianichthyidae menjadi 29, 13 diantaranya jenis endemik Sulawesi. Ikan padi, terutama jenis baru ini memberikan makna pentingnya konservasi dari biota endemik perairan tawar Sulawesi.

Homology of the median ethmoid ossifications of Aphanius fasciatus and other atherinomorph fishes

, AND G. R. CASE. 1976. Cobelodus aculeatus (Cope), an anacanthous shark from Pennsylvanian black shales of North America. Palaeontographica Abt. A Bd. 154:107-157. 3. Inte relationships of early chondricha s, p. 1-14. In: Interrelationships of fishes. P. reenw od, R. S. Miles and C. Patterson (eds.). l. . Li n. Soc., Lond., suppl. 1, 53. 1. Paleozoic Elasmobranchii, p. -115. : andb ok of paleoic thyology. Vol. 3A. H. P. ltze (ed ). Gustav Fischer Verlag, New York, , AND S. RICHARDSON, JR. 1963. The paleoecological history of two Pennsylvanian black shales. Fieldiana: Geol. Mem. 4:1-352. , AND M. WILLIAMS. 1975. New evidence on the nature of the jaw suspension in Paleozoic anacanthous sharks. Palaeontology 18:333-341.

Reproductive Histology of Tomeurus gracilis Eigenmann, 1909 (Teleostei: Atherinomorpha: Poeciliidae) With Comments on Evolution of Viviparity in Atherinomorph Fishes

Tomeurus gracilis is a species long considered pivotal in understanding the evolution of livebearing in atherinomorph fishes. Tomeurus gracilis is a zygoparous or embryoparous poeciliid: internal fertilization is followed by females laying fertilized eggs singly or retaining fertilized eggs until or near hatching. Tomeurus was hypothesized as the sister group of the viviparous poeciliids until it was proposed as a close relative of a derived viviparous poeciliid, Cnesterodon, hence nested among viviparous taxa rather than near the root of the tree. Here, we describe and compare reproductive morphological characters of the little‐known Tomeurus with those of representative atherinomorphs. In Tomeurus and Cnesterodon, sperm are packaged in naked sperm bundles, or spermatozeugmata, in a configuration considered here diagnostic of viviparous poeciliids. Testes are single and free sperm are stored in the ovary in both taxa in contrast to oviparous atherinomorphs in which testes are paired and sperm are not packaged and not stored in the ovary. Efferent ducts in Cnesterodon testes and other viviparous poeciliids have a PAS‐positive secretion demonstrating presence of a glycoprotein that inactivates sperm or prevents final sperm maturation. No PAS‐positive staining secretion was observed in Tomeurus or oviparous atherinomorphs. Tomeurus shares apomorphic reproductive characters, such as sperm bundle and testis morphology and a gonopodium, with viviparous poeciliids and plesiomorphic characters, such as a thick zona pellucida with filaments, with oviparous taxa. We do not postulate loss or reversal of viviparity in Tomeurus, and we corroborate its phylogenetic position as sister to the viviparous poeciliids. J. Morphol., 2010.