首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
We investigated the size at maturation, breeding season, and morphological development of larvae and juveniles of a freshwater pipefish Microphis leiaspis, which belongs to Gastrophori, collected from three rivers on the northern part of Okinawa-jima Island, Japan. The minimum size of brooding males was 105–123 mm in standard length (SL). The smallest mature female was estimated to be ca. 130 mm SL from the analysis of gonadosomatic index (GSI) and histological observations of gonads. The breeding season was estimated to be from June to December according to monthly changes in female GSI, histological observations of gonads, and monthly changes in the occurrence of brooding males. The number of eggs in the male brood pouch ranged from 75 to 241 (mean ± SD: 152 ± 52, n = 22). The male releases newly hatched larvae in freshwater areas. After newborns grow in the sea, they return to freshwater areas of the rivers and attain maturity. Microphis leiaspis was conformed to have an amphidromous life history. Notochord length of the released larvae was 6.1 mm, with a well-developed finfold. Larvae attained 11.1 mm SL, formation of the caudal and dorsal fin rays was complete, and the caudal fin became lozenge shaped at 30 days after the release, and juveniles reached 36.0 mm SL at 63 days after release. In the period between 30 and 63 days after the release, formation of all fins except the pectoral fins was completed, and caudal fin rays were extended and sector shaped with deep slits between each fin ray. The morphology of the released larvae of M. leiaspis is similar to that of Gastrophori species, and the morphology of juveniles similar to other species of Microphis.  相似文献   

2.
Based on our reexamination of the 9 specimens including the neotype, Bregmaceros lanceolatus is recharacterized and diagnosed by the following combination of features: caudal fin rounded; scales present on gill cover; dorsal surface of snout unpigmented or with a few chromatophores; isthmus pigmented with punctate chromatophores; two parapophyses on abdominal vertebrae; dorsal rays (D) 65–74; anal rays (A) 67–74; vertebrae (V) 58–61; longitudinal scales (LS) ca. 82–88; principal caudal rays (PC) 16–18; head length (HL)/standard length (SL) 14.0–15.5%; caudal peduncle depth/SL 3.2–4.2%. Based on 27 specimens, B. pseudolanceolatus sp. nov. is described. This species is closely similar to B. lanceolatus, but is diagnosed by the following combination of features: caudal fin rounded; scales present on gill cover; dense concentration of chromatophores on dorsal surface of snout; isthmus colorless; one board-like parapophysis on the last three abdominal vertebrae; D 58–64; A 58–67; V 52–55; LS ca. 68–77; PC 14–16; HL 15.5–18.4% SL; caudal peduncle depth 4.1–5.2% SL. Bregmaceros pseudolanceolatus is known from around the Taiwan Strait, southern East China Sea, South China Sea, Gulf of Thailand, Timor Sea, Arafura Sea, and eastern Bay of Bengal.  相似文献   

3.
 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  相似文献   

4.
Three exterilium larvae (18.2 mm notochord length to 113.3 mm standard length) of an ophidiid, Lamprogrammus shcherbachevi, from the western North Pacific are described. The specimens had a highly specialized morph with a remarkably elongate trailing gut and ventral coracoid process, and many elongate anterior dorsal fin rays, as occur in other exterilium larvae, but were characterized by unique melanophore patterns (a cluster of melanophores on the back of the stalked pectoral fin base, a row of clusters midlaterally on the trunk and caudal region, and further clusters on the trailing gut). Although the largest specimen (113.3 mm standard length, much larger than the previously recorded maximum size of exterilium larvae) retained typical features of the exterilium stage, the ventral coracoid process was significantly reduced in size compared with that of a smaller specimen (37.8 mm standard length). Comparison of the largest specimen with an adult suggests that the anterior dorsal fin rays would disappear during the transformation stage.  相似文献   

5.
Morphological development, including fin and labyrinth organ, body proportions and pigmentation, in laboratory-reared larval and juvenile climbing perch Anabas testudineus was described and behavioral features under rearing condition were observed. Body lengths (BL) of larvae and juveniles were 1.9 ± 0.1 (mean ± SD) mm just after hatching (day-0), 8.7 ± 1.3 mm on day-19, reaching 18.4 ± 2.1 mm on day-35 after hatching. Aggregate fin ray numbers attained full complements in juveniles larger than 8.3 mm BL. Preflexion larvae started feeding on day-2 following formation of the upper and lower jaws, the yolk being completely absorbed by day-7 after hatching. Teeth appeared in flexion larvae larger than 5 mm BL on day-6, with cannibalism starting shortly after and continuing with further growth. Melanophores on the body increased with growth, a large dark spot developing on the lateral midline around caudal margin of the body in the postflexion and juvenile stages. The labyrinth organ differentiated in postflexion larvae larger than 7.2 mm BL on day-16, with air-breathing starting at the same time. Body proportions attained constant in postflexion larvae larger than 7.0 mm BL, and habitat of fish shifted from bottom to mid-layer. With the exception of fin ray numbers, the above morphological developments corresponded to behavioral shifts that occurred in the postflexion stage (ca. 7 mm BL), their subsequent continuity illustrating that the species possessed most juvenile-equivalent functions from ca. 7 mm BL.  相似文献   

6.
7.
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.  相似文献   

8.
 During the R/V Hakuho-maru Cruise KH-95-2, Ocean Research Institute, University of Tokyo, from Tokyo, Japan to the South Pacific east of Australia (22° N–30° S; 126° E–176° E) from June to September, 1995, 77 unidentified gonostomatid larvae (5.5–20.0 mm SL) were collected south of 20° S with an IKMT net. They subsequently were identified as Sigmops longipinnis (Mukhacheva), and its ontogeny during the latter part of the larval stage (body form and proportions, photophores, pigmentation, and meristics) is described here. The larvae develop a species-specific row of melanophores along the midlateral line anterior to the caudal peduncle and another along the middorsal line from before the dorsal fin to just before the caudal fin. Received: June 24, 2002 / Revised: November 2, 2002 / Accepted: January 31, 2003  相似文献   

9.
A new epigonid fish, Epigonus cavaticus, is described on the basis of eight specimens (59.2–69.5 in standard length: SL) collected from a cave at depth 20 m, southern fringing reef of Ngemelis Island, Palau. The species differs from other congeners by having minute teeth on both jaws, no opercular spine, pyloric caeca 7–8, gill rakers 25–27, total pored lateral line scales 48–50, dorsal fin rays VII-I, 10–11 (mode VII-I, 10), pectoral fin rays 16, vertebrae 10 + 15, body depth 21.4–25.0% SL, pectoral fin length 22.7–24.6% SL, eye diameter 44.4–47.5% head length: HL, upper jaw length 40.2–42.5% HL. Four paratypes (63.7–66.8 mm SL) of the new species are female with mature gonads, it is the smallest in size at sexual maturity among the congeners.  相似文献   

10.
A new hairtail, Trichiurus nickolensis, is described on the basis of ten specimens collected off northwestern Australia, off the Northern Territory, and in the Gulf of Carpentaria, Queensland. The new species strongly resembles T. brevis Wang and You in Wang et al., 1992, off Hainan Island, South China Sea, and T. russelli Dutt and Thankam, 1966, off the Waltair Coast, Andhra Pradesh, India, in having the highest point of the supraoccipital crest situated directly above the posterior margin of the eye and a relatively short caudal peduncle. Trichiurus nickolensis differs from those two species in being strongly pigmented on the anterior section of the dorsal fin membrane (vs. slightly pigmented), and having a dorsal head margin that appears concave in lateral view, rises gently from snout tip to above middle of orbit, and then extends more steeply to dorsal fin origin (vs. rising gently from tip of snout to dorsal fin origin). The new species also has a greater number of dorsal fin rays (III, 138–143 vs. III, 127–132 and III, 127–131 in T. brevis and T. russelli, respectively) and total vertebrae (160–166 vs. 147–155 and 149–153), and shorter preanal length (mean 30% TL vs. 33% TL and 35% TL), head length (11% TL vs. 12% TL and 13% TL) and upper jaw length (4% TL vs. 5% TL and 5% TL).  相似文献   

11.
Parakysis notialis sp. nov. is described from the Barito River drainage in southern Borneo. It can be distinguished from congeners in having a unique combination of the following characters: head length 26.5–27.0% SL, conical head, presence of median concavity on margin of lower lip, presence of laterosensory canal pore between inner and outer mandibular barbels, branched outer mandibular barbels, branches of inner mandibular barbels separated, deeply forked caudal fin with pointed lobes, 5 pectoral fin rays, 10 branched principal caudal fin rays, sparsely pigmented caudal fin, and absence of light brown saddle from base of posteriormost dorsal fin ray to caudal peduncle. Received: February 11, 2002 / Revised: September 4, 2002 / Accepted: October 11, 2002 Acknowledgments We thank Takashige Idei for the gift of the specimens of the new species, and Darrell Siebert (BMNH), David Catania (CAS), Karsten Hartel (MCZ), Douglas Nelson (UMMZ), and Kelvin Lim (ZRC) for permission to examine material under their care. Funding from a Block Grant from the Department of Ecology and Evolutionary Biology, University of Michigan and the Rackham School of Graduate Studies, University of Michigan provided financial support for this project. Correspondence to:Heok Hee Ng  相似文献   

12.
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.  相似文献   

13.
A new species of amblycipitid catfish is here described from the Indawgyi Lake basin of the Irrawaddy River drainage in Kachin State, Myanmar as Amblyceps improcerum, new species. It can be distinguished from congeners in having a unique combination of the following characters: lower jaw longer than upper; head length 17.4–22.3% SL; head width 13.7–15.2% SL; head depth 9.0–11.7% SL; interorbital distance 31–39% HL; eye diameter 7–10% HL; 37–38 vertebrae; lateral line incomplete; predorsal length 25.5–30.7% SL; smooth posterior margin of pectoral spine; pectoral-fin length 13.5–16.8% SL; pelvic-fin length 9.6–13.4% SL; dorsal-to-adipose distance 25.2–28.7% SL; length of adipose-fin base 19.4–23.3% SL; adipose fin separate from dorsal procurrent caudal-fin rays; preanal length 62.1–66.9% SL; body depth at anus 9.8–12.8% SL; depth of caudal peduncle 10.1–12.6% SL; length of caudal peduncle 21.4–24.0% SL, post-adipose distance 15.8–17.8% SL; weakly-forked caudal fin with short broadly, rounded lobes (length of longest ray 1.3–1.5 times length of median rays); centrally projecting hooks on proximal lepidotrichia of median caudal-fin rays absent.  相似文献   

14.
A new species of opisthoproctid, Dolichopteryx pseudolongipes, is described on the basis of three specimens (48.7–79.9 mm in standard length: SL) collected from the eastern Pacific Ocean. This species is characterized by small tubular eyes (diameter 2.7–3.9% SL), presence of an adipose fin, anal fin base originating under the dorsal fin base, relatively short predorsal (73.3–73.8% SL), prepelvic (64.3–67.9% SL), preanal (77.4–80.1% SL), and preanus (71.5–75.7% SL) lengths; 31–33 (=9–10 + 22–24) gill rakers and 43–45 vertebrae. Although D. pseudolongipes had previously been confused with Dolichopteryx longipes, many differences between the species are apparent [e.g., adipose fin absent, anal fin base origin just behind dorsal fin base, greater prepelvic length (70.3–72.7% SL), 25 gill rakers, and 46–47 vertebrae in D. longipes].  相似文献   

15.
Taxonomic analysis of a group of morphologically similar ponyfishes (Perciformes: Leiognathidae) establishes a complex comprising three valid species: Leiognathus aureus Abe and Haneda, 1972, widely distributed in the western Pacific Ocean (Taiwan, Philippines, Thailand, Singapore, Indonesia, and northern Australia); L. hataii Abe and Haneda, 1972, currently known only from Ambon, Indonesia; and L. panayensis sp. nov. Kimura and Dunlap, currently known only from Panay Island, the Philippines. The L. aureus complex can be defined by the following combination of characters: mouth protruding forward, not downward; small but sharp conical teeth uniserially on jaws; a black line between lower margin of eye and lower jaw articulation; and lateral line incomplete, ending below posterior part of dorsal fin base or on anterior caudal peduncle. Leiognathus hataii differs from both L. aureus and L. panayensis in having a large dark blotch below the spinous dorsal fin base and fewer counts of scales (lateral line scales 50–58 vs. 64–85 in the latter two species; scales above lateral line 7–10 vs. 12–18; scales below lateral line 22–26 vs. 30–41). Leiognathus panayensis is distinguished from L. aureus in having a deeper body (41–51% SL vs. 35–45% SL in the latter), long posterior limb of maxilla (21–25% HL vs. 15–23% HL), wholly scaled belly (vs. naked along preanal median keel), and a dark blotch on nape (vs. absent).  相似文献   

16.
 A taxonomic review of seven-spined Polynemus species recognizes two species as valid: P. hornadayi Myers, 1936, currently known only from western Sarawak, Kalimantan, Malaysia, and P. paradiseus Linnaeus, 1758, distributed from India to Thailand and regarded as a senior synonym of P. aureus Hamilton, 1822, P. longifilis Cuvier in Cuvier and Valenciennes, 1829, P. risua Hamilton, 1822, and P. toposui Hamilton, 1822. Polynemus hornadayi differs from P. paradiseus in having a strongly protruded occipital profile (vs. nearly straight in the latter), lower counts of anal fin soft rays (mode 11 vs. 12) and gill rakers (26 vs. 32 or 33), higher counts of pectoral fin rays (18 vs. 17), scales above and below the lateral line (11 and 18 vs. 7 and 11, respectively), and pored lateral line scales (94 vs. 70), the fifth pectoral filament longest (vs. sixth), the fourth pectoral filament longer (extending well beyond the posterior central margin of the caudal fin vs. not reaching posterior central margin), a longer pectoral fin ray (posterior tip of pectoral fin reaching to midpoint of anal fin base vs. not reaching), a deeper maxilla posterior margin (mean 5% of SL vs. 4% of SL), and a well-developed swimbladder (vs. absent).  相似文献   

17.
Morphological development, including the body proportions, fins, pigmentation and labyrinth organ, in laboratory-hatched larval and juvenile three-spot gourami Trichogaster trichopterus was described. In addition, some wild larval and juvenile specimens were observed for comparison. Body lengths of larvae and juveniles were 2.5 ± 0.1 mm just after hatching (day 0) and 9.2 ± 1.4 mm on day 22, reaching 20.4 ± 5.0 mm on day 40. Aggregate fin ray numbers attained their full complements in juveniles >11.9 mm BL. Preflexion larvae started feeding on day 3 following upper and lower jaw formation, the yolk being completely absorbed by day 11. Subsequently, oblong conical teeth appeared in postflexion larvae >6.4 mm BL (day 13). Melanophores on the body increased with growth, and a large spot started forming at the caudal margin of the body in flexion postlarvae >6.7 mm BL, followed by a second large spot positioned posteriorly on the midline in postflexion larvae >8.6 mm BL. The labyrinth organ differentiated in postflexion larvae >7.9 mm BL (day 19). For eye diameter and the first soft fin ray of pelvic fin length, the proportions in laboratory-reared specimens were smaller than those in wild specimens in 18.5–24.5 mm BL. The pigmentation pattern of laboratory-reared fish did not distinctively differ from that in the wild ones. Comparisons with larval and juvenile morphology of a congener T. pectoralis revealed several distinct differences, particularly in the numbers of myomeres, pigmentations and the proportional length of the first soft fin ray of the pelvic fin.  相似文献   

18.
Eleven postflexion larvae (9.1–23.9mm standard length: SL) of a bothid, Arnoglossus elongatus, from northwestern Australian waters were described. These specimens were characterized by vertebral numbers of 11–12+32–34=43–45, slender body, remarkably elongated second dorsal fin ray, and presence of melanophores on and slightly above midlateral line of body, plus on dorsal wall of abdominal cavity and air bladder (specimens >12.6mm SL), proximally on caudal fin rays (>16.5mm SL), and on pterygiophore zones of dorsal fin and anal fin (>23.8mm SL).  相似文献   

19.
A taxonomic review of the cottid genus Cottiusculus Jordan and Starks 1904 established three species, C. nihonkaiensis sp. nov., C. schmidti, and C. gonez. Cottiusculus nihonkaiensis sp. nov., which had been previously confused with C. schmidti, is described on the basis of 32 specimens (44.8–77.9 mm, SL) collected from the Sea of Japan. The new species is very similar to C. schmidti in having a curved barbless uppermost preopercular spine and the lateral line extending past the caudal fin base, but is distinguishable as follows: nasal spines simple or sometimes weakly bicuspid (vs. deeply bicuspid in C. schmidti); first dorsal fin not elongated in either males or females (vs. elongated in males); ventral lateral and lateral line cirri present (vs. absent). The former is known from the Sea of Japan coasts of Hokkaido, Honshu, Kyushu and the Korean Peninsula, and Volcano Bay, Hokkaido, and the latter from the Pacific coast of Tohoku District, Japan. Cottiusculus gonez, known from the Sea of Japan, Sea of Okhotsk and Pacific coast of Hokkaido, is characterized by having a simple nasal spine, the uppermost preopercular spine almost straight with two small cusps dorsally, posterior cusp barbed, and the lateral line almost reaching to the caudal fin base. A lectotype of C. gonez is designated here. Sequence differences in the cytochrome b gene among the above three species of Cottiusculus are also presented.  相似文献   

20.
A pelagic juvenile (74.0 mm in standard length) of Lepidion inosimae was collected by midwater trawl (0–20 m depth) from the transition waters between the Kuroshio and Oyashio fronts off northeastern Japan. The specimen is characterized by an elongate body, a chin barbel, a minute first ray and non-elongated second ray of first dorsal fin, combination of 55 second dorsal fin rays and 52 anal fin rays, and no ventral luminous organ. This is the first report of early life stages in the genus Lepidion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号