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.
Phylogenetic relationships among families of Atheriniformes have long been problematic. The affinities of one of the most enigmatic lineages, surf silversides (Notocheiridae), have proven particularly elusive due to this taxon's unique morphology and rarity in museum collections. In this study, we use mitochondrial and nuclear sequence data to generate a phylogeny for seven of the eight families of Atheriniformes. Our results reveal that four families within Atheriniformes (Atherinopsidae, Notocheiridae, Atherinidae, Melanotaeniidae) are not monophyletic. Most notably, Notocheiridae is polyphyletic, with Notocheirus hubbsi nested within New World silversides (Atherinopsidae), while members of Iso are sister to all other Old World Atheriniforms. These data suggest that the unique morphology of Notocheirus and Iso is a result of adaptive convergent evolution to the high-energy surf habitat where these species live.  相似文献   

2.
A new species of scorpionfish, Scorpaena brevispina , is described on the basis of a single specimen collected from off the east coast of Izu Peninsula, Pacific coast of Japan, at a depth of 45 m. Scorpaena brevispina is distinguished from other Indo–Pacific species of Scorpaena by the following combination of characters: pectoral-fin rays 17; longitudinal scale rows 44; scales below lateral line 13; gill rakers 17; anterior surface of preocular spine with three vertical or slightly oblique ridges; lateral surface of maxilla without a distinct longitudinal ridge; lateral lacrimal spine present; extremely deep occipital pit; occipital pit rectangular in dorsal view, length distinctly less than width (length 53·3% of width); numerous small papillae on surface of occipital pit; pectoral fin relatively long (33·3% of standard length, L S), posterior tip extending beyond verticals through last dorsal-fin spine base and second anal-fin spine base; relatively short third to fifth dorsal-fin spines (third spine length 14·6% of L S, fourth spine 15·5%, and fifth spine 15·8%, respectively).  相似文献   

3.
Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help define some of the currently recognized species complexes were identified. Species in the “antenori complex” share at least five synapomorphies, such as ossified medial radials of dorsal and anal fins, four pectoral radials, ventral process of the maxillae enlarged, mesopterygoid long relative to the autopalatine, and proportion of cartilage in the basihyal. The “bellottii complex” is characterized by having a reduced basihyal and a deep urohyal, whereas species in the “elongatus complex” possess a caudal fin supported by four vertebrae and have unique modifications of jaw bones. The following osteological features are useful as diagnostic characters at the specific level: (1) Two vertebrae supporting the caudal fin (C. nigripinnis); (2) cartilaginous pelvic bones (C. notatus); (3) short third postcleithrum and broad lateral process of the sphenotic (C. wolterstorffi); (4) thick third postcleithrum (C. gymnoventris); (5) crest on the parietal and reduced in the upper portion of the lacrimal (C. whitei); (6) anteriorly curved lacrimal (C. cheradophilus); (7) second dermosphenotic (C. bellottii); and (8) expansion of the ventral tip of the maxillae and long basyhial (C. constanciae). J. Morphol. 238:245–262, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

4.
A new deepwater species, Enneapterygius velatus sp. nov. (Perciformes: Tripterygiidae), is described from two male specimens from Ryukyu Island, southern Japan, the holotype having been collected at a depth of 55 m and an underwater photograph taken between 30 and 41 m depth. The new species is characterized by an extremely long first dorsal-fin spine (length 31.6–34.0 % of SL), the first dorsal-fin spine bases close together, first dorsal-fin base length less than half the distance between the base of the third spine of the first dorsal-fin and origin of second dorsal-fin, first dorsal-fin spine base with developed inclinator muscles, long pelvic fins (tip of second ray extending beyond anal-fin origin), large body scales (8 circumpeduncular scales), the supratemporal sensory canals deeply U-shaped in dorsal view, snout profile weakly rounded, abdomen from between pelvic-fin bases to anal-fin origin covered by cycloid scales, body lacking significant blackish blotches and caudal-fin base with scattered melanophores in preserved specimens.  相似文献   

5.
A new stargazer,Selenoscopus turbisquamatus, is described from 30 specimens from the Kyushu-Palau Ridge, the coasts of Kii Peninsula, Japan, and the Norfolk Ridge, northern Tasman Sea. The species appears to be most closely related to the genusUranoscopus in having two dorsal fins, a spinous dorsal fin consisting of feeble spines, a stout cleithral spine, an externally visible pelvic spur, two supracleithral spines, and no postcleithrum, but differs from it in having a smooth posterior margin of the gill flap, uniserial dentary teeth, random arrangement of body scales, no subopercular spine, an intervention of the pterosphenoid (=alisphenoid) between the frontal and the parasphenoid, and the first and second haemal spines depressed on the centra. A new genus,Selenoscopus, is therefore proposed, based on these characters.  相似文献   

6.
中国贵州省穴居盲鳅一新种(鲤形目,爬鳅科)   总被引:1,自引:0,他引:1  
记述了采集于贵州省荔波县佳荣镇水井湾溶洞(25°28’N,108°06’E)适应洞穴环境的鳅类1新种:佳荣盲高原鳅Triplophysa jiarongensis sp.nov.。新种与之前记录的7种分布于西江水系的高原鳅(阿庐高原鳅、个旧盲高原鳅、长须盲高原鳅、巨头高原鳅、邱北盲高原鳅、石林盲高原鳅和天峨高原鳅)同属典型洞穴鱼类,都具有一系列与洞穴环境有关的适应性特征。新种与本属其它种类的区别主要为:胸鳍长,后伸达腹鳍起点;尾鳍微凹形;体表色素退化,光滑裸露无鳞;背鳍截形,起点位于腹鳍起点略后方;腹鳍后伸盖过泄殖孔;臀鳍截形;尾柄上下缘存在脂状鳍褶;背鳍分支鳍条8;臀鳍分支鳍条6;胸鳍分支鳍条11;脊椎骨总数4+34;眼完全退化,外观无痕迹;鳔前室被骨质鳔囊包裹,后室发达膨大呈游离膜质鳔。此外还介绍了其栖息地概况和部分生态学信息。  相似文献   

7.
Pseudobagrus brachyrhabdion sp. nov., from the Yuan Jiang and Xiang Jiang of the middle Yangtze River drainage in Hunan and Guizhou Provinces, South China, is described herein. It is distinguished from all other Pseudobagrus species with a truncate or slightly emarginated caudal fin by an unique combination of the following characters: supraoccipital plate and nuchal plate broadly interspaced and covered with skin; nasal barbels only at most reaching anterior margin of eye; maxillary barbels reaching slightly beyond posterior margin of eye; outer mandibular barbels extending to posterior margin of eye; dorsal fin with a somewhat convex distal margin, origin nearer to pectoral-fin insertion than to pelvic-fin insertion; dorsal-fin spine shorter than pectoral spine, with a somewhat serrated posterior margin; pectoral-fin spine with a smooth anterior margin; anal fin with 20–23 rays, base length 23.8–32.0% of standard length, posterior end of anal-fin base anterior to posterior end of adipose fin base; no longitudinal black band extending along flank; eyes large, diameter 16.3–23.7% of head length; and number of vertebrae 5 + 43–46.  相似文献   

8.
Evoxymetopon moricheni n. sp. is described from the northern Gulf of Aqaba, Red Sea, on the basis of a single specimen. It is characterised within the genus by a convex upper head profile; the posterior confluence of the frontal ridges slightly elevated at the nape, resulting in the presence of a slight sagittal crest; eye 5.2 times in head length; the lower hind margin of opercle slightly pointed in its lower half; the pelvic fins reduced to a scale-like structure with two soft rays on the posterior process of the basipterygium, its origin below the eighth dorsal-fin element; the first anal spine single, oval, scale like, and originating a short distance behind the vent (opposite the 34th dorsal-fin soft ray), anterior anal-fin soft rays minute and embedded, barely penetrating the skin and not visible externally, while the posterior fin supporting the rays enlarged and visible externally; approximately 17 anal-fin rays externally visible; approximately 83 dorsal-fin elements, with first spine not elongate, shorter than second; 12 pectoral-fin rays (ii + 6 + iv), with shorter anterior (fourth ray shortest) and longer posterior rays extending above the lateral line; 10 upper and 13 lower gill rakers of the first gill arch; head and body silver white, with a blackish margin anteriorly on snout and head, continuing along the anterior half of the dorsal-fin base. The new finding represents a new record of the genus from the Red Sea.  相似文献   

9.
Early morphogenesis of dorsal and pelvic fins and their supports in the larval and juvenile red-spotted grouper, Epinephelus akaara, was examined using a hatchery-reared series. The dorsal spine anlage first appeared suspended in the middle part of the finfold at ca. 2.5 mm TL. Dorsal and pelvic supports appeared by the time the fish reached ca. 3 mm and started to ossify at ca. 3.5 mm. Elongated spines and their supports developed synchronously in both dorsal and pelvic fins. The formation of dorsal fin supports proceeded from anterior to posterior. The ossification of supports was completed by ca. 33 mm. Spinelets on the second dorsal spine and pelvic spine appeared by ca. 3 mm. In specimens larger than 36 mm, all spinelets on the second dorsal spine and pelvic spine had disappeared. The maximum size of the second dorsal spine and pelvic spine lengths relative to TL were ca. 45% and 44% at 3.3 mm in fish size, respectively. Thereafter, their proportions decreased gradually. Considering the order of development of the elongated spines and mucous cells in the early life stages, the elongated spines might function as antipredator devices. Received: June 20, 2000 / Revised: April 28, 2001 / Accepted: June 11, 2001  相似文献   

10.
Chelidoperca tosaensis is described as a new species based on 84 specimens from Japan and the Philippines taken from depths of 60–302 m. The species can be distinguished from all known congeners by having the following combination of characters: scale rows between lateral line and base of spinous dorsal fin 3; pored lateral-line scales 37–42 (modally 39); scale rows in longitudinal series 39–43 (modally 40); no longitudinal dark stripe or row of dark blotches on body side. The new species is additionally characterized by having a combination of numerous, scattered, yellow spots on dorsal and anal fins with red streak or cluster of reddish spots over bases of about 4–6th dorsal-fin spines; large ocellated red spot with pinkish white border present on membrane between opercular spines; pelvic fin with middle area yellow with whitish spine, and whitish first, second and fifth soft rays; caudal fin with about three transverse rows of yellow spots centrally and posteriorly, two fan-shaped rows of red blotches on basal third, and a pair of white blotches with a pair of yellow blotches between white blotches on the base. Diagnostic characters of Chelidoperca stella, previously known only from its type locality in the Andaman Sea, are updated based on 12 specimens from Taiwan, the Gulf of Tonkin, Vietnam and the Philippines. These specimens represent the first records of the species from the Pacific Ocean.  相似文献   

11.
<正> 曲靖西冲鱼(Xichonolepis qujingensis P'an et Wang)是1978年潘江、王士涛二同志为胴甲鱼建立的一个属种。化石产在云南曲靖翠峰山徐家冲与西冲之间中泥盆统海口组的下部。建立这一属种的标本有躯甲上一件骨片的内、外印模(原作者认为系前中背片)和若干属于头甲和胸鳍甲某些散落骨片的内、外印模,材料不多,保存也不甚完好。本文系对曲靖西冲鱼形态特征的补充记述,标本是刘玉海、王俊卿和笔者等自1962年以来陆续在滇东中泥盆统采获的。最初,在武定赵家庄后山的泥灰岩层与刘氏滇鱼  相似文献   

12.
A new species of deep‐living dragonet Callionymus omanensis from Oman is described on the basis of a single male specimen collected in a trawl from 500 m depth off the coast of Oman. The new species is characterized within the subgenus Bathycallionymus by having a small branchial opening; head short (3·9 in proportion to standard length); eye large (2·4 in proportion to head length); preopercular spine with a long, upcurved main tip, with a small antrorse barb and a larger antrorse spine, and with a strong antrorse spine laterally at the preopercular‐spine base, ventral margin smooth; first dorsal fin slightly higher than second dorsal fin (male); second dorsal fin distally straight; 17 pectoral fin rays; distal end of caudal fin slightly pointed, with two median unbranched rays bearing short filaments; first dorsal fin with basal black spot reaching from first to fourth membranes, third membrane with an ocellated distal black blotch; second dorsal fin with vertical dark grey bars; distal three‐fourths of anal fin black; upper half of caudal fin with oblique dark grey bars; pelvic fin dark grey, second ray basally with a black blotch. The new species is compared with similar species. Revised keys to callionymid species of the western Indian Ocean and the Red Sea, as well as species of the subgenus Bathycallionymus, are presented.  相似文献   

13.
A review of the species and subspecies of Ditrema from East Asia recognized the following taxa: D. jordani Franz, 1910, D. temminckii pacificum subsp. nov., D. t. temminckii Bleeker, 1853, and D. viride Oshima, 1940. Ditrema jordani is characterized by a coppery-red body when fresh, the posterior end of the dorsal-fin base anterior to that of the anal-fin base, a dark rounded marking on the anterior suborbital area margined with white lines or a broad dark inverse trapezoid marking on the anterior part of the suborbital region, the lower half of the spinous portion of the dorsal fin often with a longitudinal black stripe, and a faint longitudinal dark line along the anal-fin base. Ditrema temminckii is characterized by a silvery body, usually bluish dorsally when fresh, a black oblique band on the anterior suborbital area, the spinous portion of the dorsal fin with a black distal margin, and no dark line along the anal-fin base. Ditrema t. pacificum, mainly distributed along the Pacific Ocean coast, differs from D. t. temminckii, mainly distributed along the coast of Sea of Japan, in lacking a dark spot on the anterior portion of the preopercle (vs. dark spot present in the latter), but having a black line along the posterior margin of the pelvic-fin spine (vs. black spot anteriorly on base of pelvic fin), fewer dorsal-fin spines (usually 9 or 10 vs. 10 or 11), more dorsal-fin soft rays (mode 21 vs. mode 20), and longer pectoral, pelvic, and caudal fins. The two nominal species (D. smitti and D. leave) are regarded as junior synonyms of D. t. temminckii. Ditrema viride is characterized by a silvery, dorsally yellowish-green body when fresh, 9–11 dorsal-fin spines (mode 10), a dark triangular marking on the anterior suborbital area, the spinous portion of the dorsal fin with a black distal margin, a longitudinal black line along the anal-fin base and the pelvic fin slightly darkish, and lacking a black spot anteriorly on the base. Neotypes are designated for D. jordani and D. viride. A key to the species and subspecies of Ditrema is provided.  相似文献   

14.
In order to search for armour reductions in the anti-predator armour apparatus of the threespine stickleback Gasterosteus aculeatus , we studied populations from 200 coastal lakes and 32 marine and estuarine sites in Norway. We scored the presence of reductions in the pelvic apparatus in these populations, measured the length of the second dorsal fin and pelvic spine and counted lateral plates in a subset of 96 populations. Then we looked for the relation between pelvic reduction and number of lateral plates and lengths of the second dorsal spine and pelvic spine. We also observed whether pelvic reduced fish had asymmetric development on the right or the left side of the pelvis. Pelvic reduction was not found in marine and estuarine sticklebacks (with one single exception), but in freshwater it occurred in four out of 200 lakes. The amount of pelvic reduction differed from 5% to 68% in the four populations. There appears to be a correlation between pelvic reduction and spine lengths at the population level, but not plate number. Further, it appears to be difficult to explain the occurrence of pelvic reduction in Norway with the factors proposed to be responsible for pelvic reduction in other regions.  相似文献   

15.
A new genus and species of gobiid fish,Siphonogobius nue, based on 15 specimens, is described from temperate Pacific coasts of Japan. It is unique amongst gobioids in having a simple tube-like infraorbital canal extending below the eye and the oculoscapular canal between pores A' and L' without openings, except for the terminal pores and pore D. Although well-developed infraorbital canals occur in two other gobioid genera, the rhyacichthyidRhyacichthys and the gobiidLophiogobius, such are distinct from that ofSiphonogobius in having several branches and openings. Furthermore, the new taxon is distinguished from all other gobioids by the following combination of characters: first dorsal-fin spines 7–9 (usually 8); pectoral-fin rays 24–26, the upper 7–9 rays free from the fin membrane; pelvic frenum thick, robust and slightly emarginate posteriorly; scales small and cycloid, 87–96 in longitudinal series; vertebrae 14–15+19–20=33–34 (usually 14+20=34); P-V usually 3/I II II I I I 0/11; anal-fin pterygiophores anterior to the first haemal spine 3–4 (usually 3); a row of short fleshy flaps on the ventral surface of the head, extending from the lower edge of the preopercle to the chin; anterior nostril with a minute skin flap. Axial skeletal features indicated thatSiphonogobius is closely related to a group which includesAcanthogobius and its relatives.  相似文献   

16.
The growth and morphological development of larval and juvenileEpinephelus bruneus were examined in a hatchery-reared series. Average body length (BL) of newly-hatched larvae was 1.99 mm, the larvae growing to an average of 3.96 mm by day 10, 6.97 mm by day 20, 12.8 mm by day 30, 22.1 mm by day 40 and 24.7 mm by day 45 after hatching. Newly-hatched larvae had many mucous cells in the entire body epidermis. By about 4 mm BL, the larvae had developed pigment patterns peculiar to epinepheline fishes, including melanophores on the dorsal part of the gut, on the tips of the second dorsal and pelvic fin spines, and in a cluster on the ventral surface of the tail. Spinelets on the second dorsal and pelvic fin spines, the preopercular angle spine and the supraocular spine, had started to develop by about 6 mm BL. The notochord tip was in the process of flexion in larvae of 6–8 mm BL, by which time major spines, pigments and jaw teeth had started to appear. Fin ray counts had attained the adult complement at 10 mm BL. After larvae reached 17 mm BL, elements of juvenile coloration in the form of more or less densely-pigmented patches started to appear on the body. Squamation started at 20 mm BL. Major head spines had disappeared or became relatively smaller and lost their serrations by 20–25 mm BL.  相似文献   

17.
A new owstoniine bandfish, Owstonia kamoharai, is described based on six specimens (147–402 mm in standard length) collected from off southern Japan: Shikoku Island, Kii Peninsula, and Suruga Bay. The new species differs from its congeners by the following combination of characters: dorsal-fin rays III, 21; anal-fin rays I, 14; pectoral-fin rays 21–23; total caudal-fin rays 17 (branched 13); vertebrae 28–29; gill rakers on first arch 39–40; cheek with 88–123 scales in 8–10 rows; lateral line without branch, not forming loop in front of dorsal fin, ending below 8th–10th dorsal-fin soft rays; scales in longitudinal rows 53–56; lower margin of preopercle smooth; pelvic fin short, not reaching to anus; posterior margin of caudal fin rounded; uniformly reddish coloration with black markings on membranes of both jaws; and white margins of vertical fins.  相似文献   

18.
A new species of mudskipper,Periophthalmus spilotus, is described on the basis of 16 specimens from Sumatra, Indonesia. It differs from other species ofPeriophthalmus by the following combination of characters: pelvic fins totally united into rounded disk; first dorsal fin high, greyish, no spots on fin nor elongate spines; second dorsal fin typically with 14 total elements; anal fin typically with either 14 or 15 total elements; length of anal-fin base 21.8–29.0% SL; and length of second dorsal-fin base 22.5–26.7% SL. This species is most similar to, and probably most closely related to,P. chrysospilos.  相似文献   

19.
A new perchlet, Plectranthias ryukyuensis, is described on the basis of four specimens (41.2–61.6 mm standard length: SL) from the Okinawa Islands, Japan. Plectranthias ryukyuensis can be distinguished from all congeners by the following combination of characters: X, 15 or 16 dorsal-fin rays; 14 pectoral-fin rays, all unbranched; lateral line complete, with 29 or 30 pored scales; 3 scale rows above lateral line; 5 or 6 diagonal rows of large scales on cheek between eye and corner of preopercle; preopercle with two antrorse spines on ventral margin, 20–29 serrae on posterior margin; margins of subopercle and interopercle with a few serrae (weak in large individuals); minute flaps at tips of first to ninth dorsal-fin spines; caudal fin shallowly emarginate, with some ray branches distinctively elongated past fin margin; fourth dorsal-fin spine longest, its length 110.6–128.6% that of third spine; body pinkish-white with two longitudinal rows of irregular orange-red blotches on upper half of lateral surface when fresh (rows close together in smaller than ca. 50 mm SL), blotches interconnecting anteriorly on upper and lower rows, and posterior half of lower row; four faint orange-red vertical bands below lateral line on posterior half of body and two distinct yellow blotches on cheek in fresh specimens; body uniformly yellowish-brown with two longitudinal rows of irregular dark blotches on upper half of lateral surface in preserved specimens (faint in small specimens). A key to the Japanese species of Plectranthias is given.  相似文献   

20.
N. Malchus 《Palaeontology》2004,47(6):1539-1574
A study of ligaments of larval, postlarval and adult shells of fossil and recent pteriomorphian bivalves leads to the following observations and hypotheses: (1) Ligament growth passively follows the general growth pattern of the mantle margin. No independent genetic information fixes the anterior, ventral, or posterior growth direction of the ligament. Further growth constraints relate to physical availability of space on the ligament area and to heterochronic processes. (2) The disjunct ligament and the repetition of fibrous or lamellar sublayers are phenotypic aspects of the same derived ligament Bauplan 1. All Pteriomorphia possess the ability to produce repetitive ligaments. This ability and space reductions of the ligament area in independent phylogenetic lineages are responsible for the iterative evolution of ligament grades. (3) Spondylidae and Plicatulidae are duplivincular, and the Ostreoidea are plesiomorphically multivincular. (4) Larval anterior-helical growth of the soft tissue produces opisthogyrate shells and possibly caused the evolution of the alivincular-multivincular grade. Duplivincular-alivincular and multivincular-alivincular grades can be distinguished if larval shell characters are known. (5) The taxonomic distribution of ligament grades as amended in this paper is largely consistent with modern phylogeny hypotheses based on genetic or morphologic or combined character sets. However, the resolution of early phylogenetic nodes requires more data on larval shells of Lower Palaeozoic taxa.  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