Number Of Pectoral Fin Rays Research Articles

Viability, growth and external morphology of meiotic- and mitotic-gynogenetic diploids in red sea bream, Pagrus major

Two types of gynogenetic diploids were artificially induced in the red sea bream (Pagrus major Temminck et Schlegel), either by suppressing the first cell cleavage (mitotic-G2N) or by retaining the second polar body (meiotic-G2N). The eggs of red sea bream were inseminated with UV-irradiated (3000 erg mm−2) sperm of Japanese parrot fish (Oplegnathus fasciatus Temminck et Schlegel), and hydrostatic pressure shock of 700 kg cm−2 for 5.5 min at 46 min after insemination (mitotic-G2N) and cold shock of 1 °C for 30 min at 3 min after insemination (meiotic-G2N) were applied to the eggs, sequentially. The total hatching rate and hatching rate of normal larvae of the normal diploid, meiotic-G2N and mitotic-G2N were 86.5 and 94.9%, 38.1 and 45.8%, and 12.8 and 35.0%, respectively. The induction of mitotic-G2N was confirmed by isozyme marker analysis. The standard deviations, variances and coefficients of variation of the body weight, standard length and body depth in 91-day-old juveniles were always large in mitotic-G2N, small in normal-2N and intermediate in meiotic-G2N. The variances in the number of pectoral fin rays and caudal fin rays of mitotic-G2N were significantly higher than those of normal-2N. The incidences of deformities were highest in the mitotic-G2N group. The survival rates and growth performance of the meiotic- and mitotic-G2N were significantly lower than those of normal-2N. Both G2N survived for 3 years to the adult stage.

A new sisorid catfish of the Genus Exostoma Blyth from Manipur, India

Manuscript 1546; © ZOO; Date of publication 21 December 2006 Received 01 April 2006; Revised received 13 November 2006 Finally accepted 08 December 2006 W See Images in the web supplement at www.zoosprint.org ABSTRACT A new sisorid catfish, Exostoma barakensis is described from the Iyei River (Barak drainage) of Manipur, India. It is distinguished from E. berdmorei in having deeper body, its depth 15.6 (14.0-16.5) vs. 10.9 % SL; less numbers of anal fin rays ii, 41⁄2 -5 vs. i, 6; broadly rounded vs. pointed snout; emarginated vs. deeply forked caudal fin. It differs from E. labiatum in having deeper caudal peduncle, its height 49.8 (44.1-56.7) vs. 31.2-38.7 % caudal peduncle length; interdorsal space present vs. absent; less number of pectoral fin rays i, 10-11 vs. i, 12-13; caudal emarginated vs. forked. It differs from E. vinciguerrae in having wider head, its width 88.9 (85.2-91.6) vs.105.1 (105-108) % HL; smaller eye, its diameter 9.6 (7.3-11.6) vs.16.2 (16.0-16.4) % HL. It also differs from E. stuarti in having shallower body, its depth 15.8 (14.2-16.9) vs. 18.1 % SL; longer snout, its length 59.5 (58.1-61.5) vs. 47.6 % HL; larger eye, its diameter 9.6 (7.311.6) vs. 4.7 % HL; deeper caudal peduncle, its height 49.8 (44.1-56.7) vs. 42.8 % caudal peduncle length. Exostoma vinciguerrae and E. stuarti that synonymised under E. labiatum have been examined and found to have distinguishable differences from E. labiatum, and therefore have been resurrected as valid species.

Juvenile morphology and occurrence patterns of three Butis species (Gobioidei: Eleotridae) in a mangrove estuary, southern Thailand

Juveniles of three eleotrid Butis species (B. butis, B. humeralis, and B. koilomatodon) are described; their occurrence patterns were examined in Sikao Creek, a mangrove estuary located in southern Thailand. Juveniles of each species were distinguished by the following characters: B. butis with no bands on body and pale pelvic fins; B. humeralis with no bands on body and densely pigmented pelvic fins; and B. koilomatodon with 5–6 regular bands on body and a fleshy process (preorbital knob) on the snout. Although B. butis shared the aforementioned characters with B. amboinensis found in the same estuary, the former was distinguished from the latter by having a greater number of pectoral fin rays (18–21 vs. 17) and a deeper caudal peduncle. Distribution patterns of the three Butis species in Sikao Creek were distinguishable from each other. Smaller B. butis [mean ± SD = 22.7 ± 16.9 mm in standard length (SL), n = 32] occurred in the upper reach of the estuary, while larger specimens (52.4 ± 26.2 mm SL, n = 18 and 51.5 ± 29.7 mm SL, n = 10, respectively) were found in the middle and lower reaches and none in the marine area. In B. humeralis and B. koilomatodon, only juveniles were caught except for one adult specimen each. Juveniles (8.9–16.5 mm SL, n = 79) of B. humeralis occurred in the upper and middle reaches and the marine area. B. koilomatodon juveniles (9.9–13.7 mm SL, n = 30) were distributed in all areas from the lower to upper reaches.

Developmental morphology of the cottid fish Pseudoblennius marmoratus

Embryonic, larval, and juvenile development of a Japanese cottid fish Pseudoblennius marmoratus is described from laboratory-reared specimens. Eggs of P. marmoratus resembled those of two congeners, Pseudoblennius cottoides and Pseudoblennius percoides, but differed in their smaller diameter and yolk color. Although the larvae and juveniles of P. marmoratus were also similar to them in general morphology, the former differed in the lengths of newly hatched larvae, pigmentation patterns, number of pectoral fin rays, and dorsal fin spine elongation.

Unusual number of pectoral fin rays in an Icelandic population of threespine stickleback (Gasterosteus aculeatus) recently isolated in freshwater

Threespine stickleback most often have 10 pectoral fin rays, and it seems to be a highly canalized trait. We observed an unusually high frequency of stickleback with 11 pectoral fin rays in a population recently isolated from the marine environment in a freshwater lagoon in Iceland. These new morphologies may be beneficial for the fish in the new habitat but may disappear because of strong canalizing selection for the typical 10 pectoral fin rays.

Evidence Supporting Two New Forms and One Previously Described Race Within the Cottus carolinae Species-Complex from the Ozark Highlands

I present preliminary data describing two new forms within the Cottus carolinae species-complex from the Ozark Highlands, the eyelash sculpin and the fringe-head sculpin. The eyelash and fringe-head sculpins can be diagnosed from all other species of Cottus by cirri (thin fleshy appendages), a character heretofore unknown in the genus. The eyelash sculpin can be further diagnosed by a few cirri above the eye and the fringe-head sculpin by a large number of cirri on the head and elsewhere. In addition, I provide data on pectoral fin ray number in the C. carolinae species-complex that validates the recognition of the Black River race in the Ozark Highlands (18–19 in Black River race, 13–17 in all other C. carolinae). The distribution of Ozark Highland members of the C. carolinae species-complex and a new size record are also discussed.

Genetic and morphological identification of Sebastiscus tertius in the East China Sea (Scorpaeniformes: Scorpaenidae)

The allozymes and morphology of 110 specimens of three Sebastiscus species (S. marmoratus, S. tertius, and S. albofasciatus) in the East China Sea and near Japan were compared. Results of 20 allozyme loci studied showed that all three species were closely related (Nei's unbiased genetic distances, 0.057–0.133) but could be identified on the basis of informative loci with a few exceptions. Initial identification based on color patterns agreed with allozyme identification in more than 98% of Sebastiscus specimens and agreed completely in S. albofasciatus. One specimen that was initially identified as S. marmoratus because of the dark body color was actually S. tertius according to two informative allozyme loci. Number of pectoral fin rays differed between S. marmoratus (18 or fewer, 98%) and S. tertius (19 or more, 85%) in this study. The previously mentioned dark specimen had 19 pectoral fin rays, which are characteristic in S. tertius. Using seven morphological measurements, canonical discriminant analysis between S. marmoratus and S. tertius classified less than 90% of specimens into the original groups (species). Some specimens of S. tertius resembled S. marmoratus in body shape and vice versa. A combination of genetic characterization and morphological examination is necessary to identify S. marmoratus and S. tertius accurately. Distinction based on allozymes and color patterns with numbers of pectoral fin rays should provide satisfactory identification.

A new zoarcid, Lycodes mcallisteri , from eastern Arctic Canada (Teleostei: Perciformes)

A new zoarcid fish, Lycodes mcallisteri, is described on the basis of nine specimens (230–375 mm SL) from eastern Arctic Canada, Nunavut (Hudson Strait, 298 m; Cumberland Sound and Baffin Bay, 579 m). It resembles about 15 other Lycodes spp. in having a long tail and a "ventromediolateral" type of lateral line. It is distinguished from Arctic members of this group (Lycodes marisalbi, L. palearis, and L. sagittarius) by the high number of pectoral fin rays (22–23), short pelvic fins, low submental crests, and coloration (6–10 light patches dorsally). It resembles two Pacific species (L. macrochir and L. soldatovi) by the high number of pectoral fin rays, but differs by coloration, meristics, and shape of the pectoral fin.

PECTORAL FIN ASYMMETRY, DIMORPHISM AND FECUNDITY IN THE BROOK STICKLEBACK, CULAEA INCONSTANS

AbstractSexual dimorphism in the pectoral fins of a C. inconstans population produces males whose fins are relatively larger than those of females. This difference may result from the unique demands placed on the fins during the male's courtship dance and fanning behaviour during the parental phase. Males and females are also dimorphic in terms of fluctuating asymmetry (FA) of pectoral fin ray number, which is lowest in females. Females with symmetric fin ray counts averaged about 15% more eggs per clutch than females with asymmetric fin ray counts. The ovaries of symmetric females were an average 6.5% heavier than those of asymmetric fish. The difference in fecundity is statistically significant and similar in two samples collected from the same site and separated by a time span of 19 years. This is the first report of a correlation between FA and fecundity in a fish population.

Embryonic, larval and juvenile development of the roughskin sculpin,Trachidermus fasciatus (Scorpaeniformes: Cottidae)

Embryonic, larval and juvenile development of the catadromous roughskin sculpin,Trachidermus fasciatus, were described using eggs spawned in an aquarium. The eggs, measuring 1.98–2.21 mm in diameter, were light reddish-yellow and had many oil globules, 0.05–0.18 mm in diameter. Hatching occurred 30 days after spawning at 2.3–11.3°C. The newly-hatched larvae, measuring 6.9–7.3 mm BL, had a single oil globule, 9–10+25–26=34–36 myomeres and 6 or 7 large stellate melanophores dorsally along the gut. The yolk was almost resorbed, number of pectoral-fin rays attained 16–17, and two parietal, one nuchal and four preopercular spines were formed, 5 days after hatching, at 8.2–8.4 mm BL. The oil globule disappeared, and one supracleithral spine was formed, 11 days after hatching, at 8.9–9.5 mm BL. Notochord flexion began 15 days after hatching, at 9.7–10.3 mm BL. A posttemporal spine was formed 20 days after hatching, at 10.7–10.9 mm BL. The first dorsal fin spines (VII–VIII), second dorsal fin and anal fin rays (18–19, 16–18, respectively) appeared 23 days after hatching, at 12.0–13.7 mm BL. The pelvic fin spine and rays (I, 4) were formed and black bands on the head and sides of the body began to develop 27 days after hatching, at 13.8–15.8 mm BL.

Bolinia euryptera, a New Genus and Species of Sculpin (Scorpaeniformes: Cottidae) from the Bering Sea

A new genus and species of cottid is described from the Aleutian Ids., Alaska. It is characterized by having a large number of pectoral-fin rays, depressed and scaleless head and body, strongly hooked upper preopercular spine, descending spine on the lateral surface of the preopercle, and two rows of lateral-line pores. It is hypothesized to be the sister group of a monophyletic group containing Artediellus and its relatives.

A new subspecies of the ayu,Plecoglossus altivelis, (Plecoglossidae) from the Ryukyu Islands

A new subspecies of the ayu,Plecoglossus altivelis ryukyucnsis, is described on the basis of specimens from Amami-oshima and Okinawa Islands, the Ryukyu Islands, Japan. This new subspecies is distinguished fromP. altivelis altivelis by the fewer numbers of pectoral fin rays, longitudinal scales and scales above and below the lateral line, and also by the unique electrophoretic mobilities of several enzymes.

The effect of spawning time and incubation temperature on meristic variation in chum salmon (Oncorhynchus keta)

Variability in the number of dorsal, anal, caudal, pectoral, and pelvic fin rays, vertebrae, and gill rakers of early and late spawning stocks of Chehalis River chum salmon (Oncorhynchus keta) incubated under controlled water temperatures of 4, 8, and 12 °C was examined. The early spawning stock had fewer dorsal fin rays, more anal fin rays, fewer pectoral and pelvic fin rays, and fewer gill rakers than did the late spawning stock. Chum salmon originally incubated at 4 °C had the lowest number of dorsal fin rays, but the highest number of vertebrae and gill rakers. Chum salmon originally incubated at 8 °C had the highest number of anal fin rays, and those incubated at 12 °C had the highest number of pectoral fin rays. Meristic phenotypes had both a genetic and an environmental component.

The influence of temperature change on number of pectoral fin rays developing in Fundulus majalis (Walbaum)

The influence of temperature change on number of pectoral fin rays developing in Fundulus majalis (Walbaum)

Meristic Differences between Spring- and Autumn-Spawning Atlantic Herring (Clupea harengus harengus) from Southwestern Newfoundland

Numbers of vertebrae, gill rakers, and of pectoral, anal, and dorsal fin rays of spring- and autumn-spawning Atlantic herring (Clupea harengus harengus Linnaeus) in 10 samples from the coastal waters of southwestern Newfoundland were compared. There was no significant difference (P > 0.05) between mean vertebral numbers of spring and autumn spawners. Mean numbers of gill rakers and of pectoral, anal, and dorsal fin rays were all higher (P < 0.01) for autumn spawners than for spring spawners with gill-raker and pectoral fin-ray numbers exhibiting the greatest degree of difference. It is suggested that the differences in fin-ray numbers between spring and autumn spawners are related to water temperatures during larval development and to differences in developmental rates of spring- and autumn-hatched larvae.

Racial divergence in fin ray variation patterns inGasterosteus aculeatus

1. Dorsal, anal and pectoral fin ray numbers are shown to be modifiable by temperature and salinity conditions during embryonic development, in both western European population groups ofGasterosteus aculeatus. This modification follows a characteristic pattern in relation to both factors mentioned. Temperature lability varies from low to high according to the salinity. 2. The temperature variation pattern is different for the two population groups. High temperature lability in dorsal and anal fin rays is shown to exist at low concentrations for the fresh-water populations (A-type), at high salinities for the salt-water populations (B-type). Modification of dorsal and anal fin rays is almost absent at high concentrations for theA-type, at low concentrations for theB-type. Pectoral fin rays show a reversed pattern in each of the groups. 3. The results are discussed with respect to the facts reported from natural populations, and as to their bearings on the methods employed in the study of evolutionary divergence.