Evidence of genetic and environmental influences on meristic variation in the rainbow trout,Salmo gairdneri Richardson

Synopsis An investigation of the effect of parentage and temperature on the expression of selected meristic characters of rainbow trout, Salmo gairdneri, reveals statistical differences in the number of vertebrae, dorsal fin rays and anal fin rays among test batches of progeny of different parentage. Batches of fertilized ova of the same stock or parentage, when incubated at 9.5 °C and 14.8 °C, produced lower mean dorsal and anal fin ray counts and a higher mean pectoral fin ray count at the higher temperature. Incubation temperature had no significant effect on the number of vertebrae.Significant statistical differences occurring in various characters among groups of rainbow trout of different parental origin provide convincing evidence of genetic inputs into meristic expression. However, the existence of both environmental and genetic inputs into meristic expression in rainbow trout necessitates further investigation before the meaning of observed meristic plasticity in rainbow trout can be resolved.     

The median‐fin skeleton of the Eastern Atlantic and Mediterranean clingfishes Lepadogaster lepadogaster (Bonnaterre) and Gouania wildenowi (Risso) (Teleostei: Gobiesocidae)

Previous research on the osteology of the Gobiesocidae focused mostly on the neurocranium and the thoracic sucking disc (formed by the paired‐fin girdles). Little attention has been paid to the skeleton of the median fins. The dorsal‐ and anal‐fin skeleton of Lepadogaster lepadogaster and other gobiesocids (excluding Alabes, which lacks these fins) are characterized by the absence of spines, branched fin‐rays, and middle radials. In gobiesocids, the distal radials never ossify and consist of elastic hyaline‐cell cartilage. Gouania wildenowi is unique among gobiesocids in having further reductions of the dorsal‐ and anal‐fin skeleton, including a notable decrease in the size of the proximal‐middle radials in an anterior–posterior direction. Unlike L. lepadogaster, which exhibits a one‐to‐one relationship between the dorsal‐ and anal‐fin rays and proximal‐middle radials, G. wildenowi has a higher number of proximal‐middle radials than distal radial cartilages and fin rays in the dorsal and anal fins. In G. wildenowi, the dorsal‐ and anal‐fin rays do not articulate with the distal tip of the proximal‐middle radials but are instead positioned between proximal‐middle radials, which is unusual for teleosts. Previously unrecognized dorsal and ventral pads of elastic hyaline‐cell cartilage are also present in the caudal skeleton of L. lepadogaster, G. wildenowi, and all other gobiesocids examined. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

Redescription of <Emphasis Type="Italic">Bregmaceros mcclellandi</Emphasis> Thompson, 1840 (Gadiformes: Bregmacerotidae)

 This study redescribes Bregmaceros mcclellandi Thompson, 1840, based on one specimen (74.4 mm SL) from the Bay of Bengal and 66 specimens (30.0–84.7 mm SL) from Mumbai (Bombay), India, because the type specimens have apparently been lost. The present specimens are characterized by having black dorsal, pectoral, and caudal fins and show the following morphology: caudal fin slightly forked; body chromatophores present mainly at the dorsal part; no scales on cheek; vertebrae 52–55 (13–15 + 38–41); dorsal rays 52–59; anal rays 54–60; pectoral rays 18–20; caudal rays 27–31 (principal rays 14); transverse scales 14–15. In the 66 Mumbai specimens, it was confirmed that the distinctive black fin pigmentation developed sequentially with growth, with complete pigmentation first on the anterior lobe of the dorsal fin, then simultaneously on the posterior lobe of the dorsal fin, the caudal fin, and the pectoral fin, and last, on the anal fin. This species is known only from the Arabian Sea, Bay of Bengal, and Gulf of Thailand. A review of 16 nominal Bregmaceros species indicates that, besides B. mcclellandi, the distinctive dark fin pigmentation is found in B. atripinnis (Tickell), B. atlanticus Goode and Bean, B. japonicus Tanaka, and B. lanceolatus Shen. B. atripinnis is considered a junior synonym of B. mcclellandi, and the others are clearly distinct from B. mcclellandi. Comments are made on some of the characters to more fully characterize the species and for reference in future revisionary and phylogenetic studies. Received: June 17, 2002 / Revised: December 2, 2002 / Accepted: December 24, 2002     

A larva of Coryphaenoides pectoralis (Gadiformes: Macrouridae) collected by deep-sea submersible from off Hokkaido, Japan

A late-stage larva of Coryphaenoides pectoralis was first observed in situ and subsequently collected by the deep-sea submersible “Shinkai 2000” from mesopelagic waters at a depth of 530 m off Hokkaido, Japan. The larva (14.5 mm in head length, 149+ mm in total length) has fan-like pectoral fins, elongate first dorsal fin, pelvic fin and tail, 10 first dorsal rays (including 2 pseudospines), and 7 pelvic fin rays, 6 branchiostegal rays, no light organ, anus just anterior to anal fin origin, 2 retia and gas glands, 14 abdominal vertebrae, and previously reported larval pigmentation. Counts of second dorsal and anal fin rays, and caudal vertebrae, are reported for the first time.     

A new loach, Cobitis shikokuensis (Teleostei: Cobitidae), from Shikoku Island, Japan

A new species of spinous loach, Cobitis shikokuensis, is described based on 297 specimens from Shikoku Island, Japan. The new species was formerly known as the Shikoku group of Cobitis takatsuensis. It can be distinguished from other species of Cobitis and closely related genera by a combination of the following characters: dorsal fin with 6 branched soft rays; anal fin with 5 branched soft rays; one brownish streak across eye from the tip of nose, no streak on cheek; a black spot smaller than eye diameter near the dorsal corner of the caudal fin base; 3–5 small brownish speckles on ventral side of caudal peduncle; high caudal peduncle with well-developed fleshy keels on dorsal and ventral side; a lamina circularis at base of dorsal part of pectoral fin absent; first branched soft ray of pectoral fin broad in males; pectoral soft rays widely branched from the approximate midpoint; last anal fin ray with 2 elements; interorbital width 11.2–17.1% of head length.     

Skeletal characterization of wild and reared zebrafish: anomalies and meristic characters

Among two groups of wild and reared zebrafishes (zf) Danio rerio, all meristic characters considered were variable except the numbers of rays and pterygophores of the dorsal fin and the principal caudal fin rays, which tended to be canalized. Wild and reared individuals differed in the number of intervertebrae and anal pterygophores, and the dorsal and anal fin insertion. There were some skeletal anomalies of vertebrae and fins, particularly the caudal fin. Cephalic and Weber-apparatus anomalies were rare. Types and frequencies of anomalies were quite similar in the two zf groups, but differences emerged for several less frequent anomalies. Such differences and the phenotypic variability of D. rerio make this species a perfect teleost model for investigating the influence of experimental or unfavourable environmental conditions on skeletal development of both domesticated and wild fish.     

A new cottid species, Icelus sekii (Perciformes: Cottoidei), from Hokkaido, Japan

A new cottid species, Icelus sekii, is described on the basis of six specimens collected from off Rausu and Urakawa, Hokkaido Island, Japan. This species is distinguished from its congeners by the following combination of characters: supraocular and parietal spines absent; nuchal spine obscure; uppermost preopercular spine unbranched; no scales between dorsal scale row and lateral line scale row, and no scales below lateral line scale row; supraocular, parietal, and nuchal cirri present; five dark brown saddles dorsolaterally; anal fin rays 13; pectoral fin rays 15; vertebrae 12 + 24–25 = 36–37. Icelus sekii can be mature at the smallest size among the species of Icelus. As a secondary sexual character, the male holotype has unique ensiform flaps on the distal tips of the first dorsal fin.     

Rhodeus pseudosericeus sp. nov., a new bitterling from South Korea (Cyprinidae, Acheilognathinae)

A new bitterling, Rhodeus pseudosericeus sp. nov., is described on the basis of 31 specimens from five localities included in the Namhan River system, South Korea. The new species is distinguished from other Rhodeus species by the following combination of characters: branched dorsal fin rays 9–10 (mode 9); branched anal fin rays 9–11 (mode 10); longest simple ray of dorsal fin strong and stiff, distally segmented; pelvic fin rays i, 6–7; iris of males blackish; dorsal and anal fins of males grayish in breeding season; karyotype with 2n = 48 (8m + 20sm + 20st). Rhodeus pseudosericeus sp. nov. is similar to Rhodeus sericeus sericeus in the number of pelvic fin and branched dorsal fin rays and the melanophores present on the dorsal fin membrane, but differs from the latter in having a greater body depth, more branched anal fin rays, fewer vertebrae, a lower number of scales in the lateral series, and differing male nuptial coloration. Received: June 30, 2000 / Revised: February 21, 2001 / Accepted: March 6, 2001     

A new pearleye (Teleostei,Aulopiformes) species from the Oligocene of Romania

A new pearleye species of the alepisauroid family Scopelarchidae, Scopelarchoides neamticus sp. nov., is described herein based on two specimens from the Oligocene Lower Dysodilic Shales Formation, cropping out in the Pietricica Mountain, Romanian Eastern Carpathians. The new species described herein exhibits a unique combination of features (including head length about 25% of SL; coracoid remarkably expanded; both preorbital and postorbital lengths larger than orbit diameter; 50 or 51 vertebrae; dorsal fin with nine or ten rays; anal-fin with 28 rays; length of anal fin base about 30% of SL; preanal distance almost 60% of SL; pelvic fin insertion located just under the second dorsal fin ray; pectoral fins only slightly longer than pelvic fins; caudal fin with 19 principal rays plus 14 upper and 13 lower procurrent rays) that justifies its recognition as a new species of the genus Scopelarchoides. Both morphological and meristic features suggest a certain degree of similarity between S. neamticus sp. nov. and the extant species Scopelarchoides signifer. The fossils of the new Oligocene species described herein represent the oldest known skeletal record of Scopelarchidae.     

Batoid wing skeletal structure: novel morphologies, mechanical implications, and phylogenetic patterns

The skeleton of the "wings" of skates and rays consists of a series of radially oriented cartilaginous fin rays emanating from a modified pectoral girdle. Each fin ray consists of small, laterally oriented skeletal elements, radials, traditionally represented as simple cylindrical building blocks. High-resolution radiography reveals the pattern of calcification in batoid wing elements, and their organization within the fin ray, to be considerably more complex and phylogenetically variable than previously thought. Calcification patterns of radials varied between families, as well as within individual pectoral fins. Oscillatory swimmers show structural interconnections between fin rays in central areas of the wing. Morphological variation was strongly predictive of locomotor strategy, which we attribute to oscillatory swimmers needing different areas of the wing stiffened than do undulatory swimmers. Contributions of various forms of calcification to radial stiffness were calculated theoretically. Results indicate that radials completely covered by mineralized tissue ("crustal calcification") were stiffer than those that were calcified in chain-like patterns ("catenated calcification"). Mapping this functionally important variation onto a phylogeny reveals a more complicated pattern than the literature suggests for the evolution of locomotor mode. Therefore, further investigation into the phylogenetic distribution of swimming mode is warranted.     

Hemimyzon sheni, a new species of balitorid fish (Teleostei: Balitoridae) from Taiwan

A new balitord fish, Hemimyzon sheni n. sp. was collected from the Tar-Ju River basin, Taitung County, southeast Taiwan. The new endemic species can be distinguished from other congeneric species by a combination of the following features: (1) dorsal fin rays 3 + 8, pectoral fin rays 13+11 (total 24); (2) lateral-line scales 78–80 and predorsal scales 31–32; (3) somewhat pointed head shape; (3) small pelvic fin which does not extend to rear vertical of dorsal fin; (4) position of anus close to anal fin base; and (5) predorsal region with many very small light brown marks and unmarked pectoral fin. A diagnostic key to three nominal, endemic species of Hemimyzon from Taiwan is also provided in this paper.     

Osteological development in the Japanese sardine,Sardinops melanostictus

The development of all osteological elements, except scales, of the Japanese sardine,Sardinops melanostictus, is described from newly-hatched larvae to adult fishes. Newly-hatched larvae lacked osteological elements. Part of the head skeleton began to develop in 53 hour old larvae (4.2 mm in notochord length [NL]). Larvae at the first-feeding stage (77 hours, 5.5 mm NL) possessed several elements of the head skeleton and pectoral fin supports. In a 10.5 mm NL specimen, part of the caudal and dorsal fin supports were apparent. The centra appeared in specimens 18–22.7 mm in standard length (SL). Gill rakers were first observed in the lower branchial arches at 13 mm NL and spine-like processes with spiny nodules from about 25 mm SL. The distance between the predorsal and first dorsal proximal radial relative to SL rapidly decreased with forward translocation of the dorsal fin and became constant beyond approximately 34 mm SL. At this stage, most basic osteological elements were established. Completion of the osteological structure was characterized by the disappearance of the dentary teeth at 60–70 mm SL. Based on the osteological development, ontogenetic intervals consisting of four periods and eight phases were recognized.     

Schindleria elongata,a new species of paedomorphic gobioid from the Red Sea (Teleostei: Schindleriidae)

A new species of paedomorphic gobioid, Schindleria elongata, from the Red Sea, is described on the basis of five specimens. The new species is characterized by its lack of body pigmentation; the body depth at pectoral‐fin origin 4–5% of standard length (L_S) and at anal‐fin origin 5–7% L_S; the predorsal length 66–70% L_S; pre‐anal length 66–71% L_S; dorsal‐fin rays 13 or 14; anal‐fin rays 10 or 11; first dorsal‐fin ray at myomere 20 or 21; first anal‐fin ray below second to fourth dorsal‐fin rays; myomeres 19 or 20 + 13 or 14 = 33 or 34 total; premaxillae and dentaries with small teeth; gas bladder located posteriorly at 56–60% L_S; males with a rod‐like, flexible urogenital papilla lacking lobes, projections or accessory papillae, with distal half tapering to a broad, angular point and usually posteriorly directed. A key to the species of Schindleriidae is presented.     

<Emphasis Type="Italic">Careproctus parvidiscus</Emphasis>, a new species of liparid fish (Teleostei: Scorpaeniformes) collected from the southern Okhotsk Sea,Japan

 A new liparid, Careproctus parvidiscus, is described on the basis of a single specimen (177 mm in standard length) collected from the southern Okhotsk Sea, off Shiretoko Point, Hokkaido, Japan, at 400–700 m depth. It is distinguished from other congeners by the following combination of the characters: 50 dorsal fin rays, 44 anal fin rays, 10 + 47 = 57 vertebrae, 2 pleural ribs, 14 pyloric caeca being slender and pointed, 2 suprabranchial pores, narrower gill opening, longer lower lobe of pectoral fin, base of uppermost pectoral fin ray almost on a level with center of eye, rudimentary disk, dusky peritoneum, and black stomach. Received: June 13, 2001 / Revised: December 7, 2001 / Accepted: December 22, 2001     

A new species of <Emphasis Type="Italic">Rhinogobius</Emphasis> (Teleostei: Gobiidae) from the Feiyunjiang Basin in Zhejiang Province,China

A new freshwater goby, Rhinogobius wuyanlingensis, was collected from Wuyanling National Natural Conservation Area, Taishun, Zhejiang Province, China. The species can be distinguished from all congeneric species by the following unique combination of features: second dorsal fin rays modally I, 8; anal fin rays I, 8; pectoral fin rays modally 18; longitudinal scale series 30–32; predorsal scales 7–9; vertebral count 10 + 17 = 27; body always with six longitudinal pinkish orange to grayish brown lines from dorsal to ventral region in male; cheek spotless; branchiostegal membrane deep grayish with 6–7 long, transverse deep red stripes in male; chin always deep grayish; first dorsal fin with two long black blotches on membranes anterior to third spinous ray in male; second dorsal fin whitish with three to four horizontal rows of light spots in male; caudal fin base with a large blackish-brown spot; and pectoral fin with a horizontal, median blackish brown line. An artificial key to all five nominal species with a high vertebral count (27–29) from Zhejiang Province from China is also provided.     

<Emphasis Type="Italic">Acheilognathus striatus</Emphasis> (Family: Cyprinidae), a new bitterling species from the lower Yangtze River,China

A new species of bitterling, Acheilognathus striatus sp. nov., is described on the basis of 57 specimens collected from the lower Yangtze River in Jiangxi Province, China. It can be distinguished from all congeners by the following combined characters: a pair of relatively long barbels, slightly longer than half of eye diameter; dorsal fin with three simple and 8–9 branched fin rays, anal fin with three simple and 7–8 branched fin rays; a black longitudinal stripe on body from the base of caudal peduncle, distinctly reaching anteriorly to the vertical line from the origin of dorsal fin, broader in males than in females; a scale distance between the longitudinal stripe and lateral line below the origin of dorsal fin; dorsal and anal fin margined with black band in males.     

A new species of the genusamblyeleotris (pisces: Gobiidae) from Japan

A new shrimp-associated goby,Amblyeleotris melanocephala, is described on the basis of specimens from Okinoshima Island. Kochi Prefecture, and Okinawa Island, Okinawa Prefecture, Japan. The species is distinguished from other members of the genus by the following combination of characters: head dark brown, a few yellow spots on pectoral fin base and opercular margin, 13 second dorsal and 13 anal fin soft rays, 20 pectoral fin rays, longitudinal scales 92–101, proportional length of interpelvic connecting membrane relative to longest pelvic fin ray (CM-value) 0.46–0.55, presence of a ventral frenum, midline of nape naked, sides scaled above midpoint between preopercle and opercle.     

Channa panaw, a new channid fish from the Irrawaddy and Sittang River basins, Myanmar

Channa panaw sp. nov. (Channidae) is described from 32 specimens collected from the Irrawaddy and Sittang River basins, Myanmar. It is distinguishable from all known congeners by the combination of the following characters: 32–35 dorsal fin rays, 23–24 anal fin rays, 17–20 pectoral fin rays, 39–41 lateral line scales, 39–41 total vertebrae, one large scale on each side of the lower jaw (rarely 2 on one side), pelvic fin length always more than 50% of pectoral fin length, and 7–12 irregular black blotches on the upper half of the body.     

<Emphasis Type="Italic">Samariscus multiradiatus</Emphasis>, a new dextral flounder (Pleuronectiformes: Samaridae) from New Caledonia

A new dextral flounder, Samariscus multiradiatus, is described from six specimens (four males and two females) collected in deep waters (296–430 m) around New Caledonia. The species is easily distinguished from its 16 congeners in having a combination of 85–91 dorsal fin rays, 67–72 anal fin rays, 5 pectoral fin rays, and 9 abdominal and 34–35 caudal vertebrae.