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1.
The morphology of the early stage of Eumegistus was described from three specimens [E. brevorti: 23.0 mm in standard length (SL) juvenile; E. illustris: 5.8 mm SL postflexion larva, and 40.0 mm SL juvenile] recently rediscovered in museum collections. Larval and juvenile pigmentation
patterns were reported for the first time for this genus. The 5.8 mm SL postflexion larva of E. illustris had pigmentation on the head and anterior half of the body, through to the middle of the dorsal fin base. In larvae and juveniles
of both species, the outer side of the pelvic fin was pigmented. The two juveniles possessed several spines on the lachrymal
and protruding rays in the middle of the caudal fin. Although it is known previously that the notochord flexion occurs at
5.0–6.0 mm SL in E. brevorti, the reexamined 5.0 mm SL specimen had the notochord completely flexed. Furthermore, we could not confirm whether the previously
studied 4.0 mm SL specimen was E. brevorti because it was badly damaged. 相似文献
2.
Embryonic, larval, and juvenile development of a small cyprinid species, Tanichthys albonubes, is described from laboratory-reared specimens. The eggs, measuring 1.0–1.2 mm in diameter, were demersal, almost spherical
in shape, transparent and unpigmented, with a pale yolk without oil globules. Hatching occurred 45–53 h after fertilization
at 25.5°–26.9°C. The newly hatched larvae, measuring 2.2–2.6 mm in body length (BL), had melanophores on the head and body.
In particular, a dark vertical streak occurring posterior to the otic capsule and melanophores above the eyes were distinctive.
The yolk was completely absorbed at 3.4 mm BL. Notochord flexion was initiated at 5.0 mm BL and finished at 6.0 mm BL. Aggregate
numbers of all fin rays were completed at 11 mm BL. Squamation was initiated at 8.4 mm BL and completed at 13 mm BL. Although
the eggs of T. albonubes resembled those of other small danionin species, including Aphyocypris chinensis, Chela dadiburjori, Danio rerio, Devario malabaricus, Gobiocypris rarus, Hemigrammocypris rasborella, and Horadandia atukorali, they differed from those of A. chinensis, C. dadiburjori, G. rarus, and Horadandia atukorali in having a wider perivitelline space. The larvae and juveniles of T. albonubes were similar to those of the aforementioned seven species plus Danio albolineatus, Danio kerri, and Devario sp. (cf. D. aequipinnatus) in general morphology. However, the early life stage morphology of T. albonubes differed from them in having a dark vertical streak posterior to the otic capsule and melanophores above the eyes in the
yolk sac larval stage, and a dark lateral streak with an unpigmented area just above the former on the body, a dark blotch
on the caudal fin, and reddish dorsal, anal, and caudal fins during the postflexion larval and juvenile stages. 相似文献
3.
The morphology of eggs and larvae of Awaous melanocephalus is described. The eggs measured 0.33–0.35 mm in long-axis diameter and 0.32–0.34 mm in short-axis diameter. Newly hatched
larvae (0.90–0.99 mm in notochord length, NL; 0.93–1.04 mm in total length, TL) were poorly developed, lacking a mouth and
having a large yolk sac and unpigmented eyes. The mouth opened and the eyes became fully pigmented 3 days after hatching (1.78–2.00 mm
NL, 1.88–2.10 mm TL). The yolk sac was completely absorbed 5 days after hatching at a water temperature of 27°–28°C. 相似文献
4.
Embryonic, larval, and juvenile development of a Myanmarese cyprinid fish, Inlecypris auropurpureus, is described from laboratory-reared specimens. The eggs, measuring 0.9–1.0 mm in diameter, were demersal, almost spherical
in shape, transparent and unpigmented, with a pale yellow yolk without oil globules. Hatching occurred 49–56 h after fertilization
at 26.2°–27.3°C. The newly hatched larvae, measuring 2.9–3.1 mm in body length (BL) with 17 + 19–20 = 36–37 myomeres, had
melanophores on the head and body. A cement organ on the forehead for adhering to objects during the yolk sac and early preflexion
larval stages was distinctive. The yolk was completely absorbed at 3.6–4.0 mm BL. Notochord flexion was initiated at 5.1–5.6 mm
BL and finished at 7.1 mm BL. Aggregate numbers of all fin rays were completed at 14 mm BL. Squamation was initiated midlaterally
on the anterior trunk at 14 mm BL and completed at 27 mm BL. Although the eggs of I. auropurpureus resembled those of the closely related species Chela dadiburjori, Danio rerio, and Devario malabaricus, they differed from those of Danio rerio and Devario malabaricus in having a narrower perivitelline space. The larvae and juveniles of I. auropurpureus were also similar to those of C. dadiburjori, Danio rerio, and Devario malabaricus in general morphology, but they differed from the latter three species in having a series of dark blotches laterally on the
body in the juvenile stage. Moreover, I. auropurpureus differed from C. dadiburjori in having more myomeres and a near-single row of melanophores on the body along the dorsal midline from the yolk-sac to early
postflexion larval stages, from Danio rerio in having a cement organ on the forehead during the yolk-sac and early preflexion larvae, and a single melanophore on the
lower eye margin in the early yolk-sac larvae, and from Devario malabaricus in having a single melanophore on the lower eye margin in the early yolk-sac larvae. The presence of a cement organ on the
forehead indicates a close relationship among the genera Inlecypris, Chela, and Devario. 相似文献
5.
The embryonic, larval and juvenile development of blue whiting,Sillago parvisquamis Gill, are described from a series of laboratory-reared specimens. Mean egg diameter and mean total length (TL) of newly-hatched
larvae were 0.71 mm and 1.58 mm, respectively. The eggs were non-adhesive, buoyant and spherical with an oil globule (mean
diameter 0.18 mm). Hatching occurred about 20 hours after fertilization at a temperature of 24.0–25.0°C, newly-hatched larvae
having 38–40 myomeres. The yolk and oil globule were completely absorbed 3 days after hatching at 2.8–3.2 (mean 3.0) mm TL.
Notochord flexion was completed by 7.2–8.2 (7.7) mm TL, and pectoral and caudal fin rays fully developed by approximately
10 mm and 8.5 mm TL, respectively. Completion of fin development occurred in the following sequence: caudal, pectoral, anal
and second dorsal, first dorsal and pelvic, the last-mentioned by approximately 11 mm TL. The larvae ofS. parvisquamis andS. japonica, which closely resemble each other in general morphology and pigmentation, could be distinguished as follows. Newly-hatchedS. parvisquamis larvae had more myomeres thanS. japonica (38–40 vs. 32–34) and more melanophores on the dorsal surface of the body (19–28 vs. about 40).Sillago japonica had a vertical band of melanophores on the caudal peduncle, which was lacking in postflexionS. parvisquamis larvae. In addition, juveniles ofS. parvisquamis (larger than 23 mm TL) had melanophores on the body extending anteriorly to below the lateral line to form a midlateral band,
whereas no obvious band occurred on similarly-sizedS. japonica juveniles. 相似文献
6.
Embryonic and larval development of an Indian cyprinid fish, Barilius canarensis, is described from laboratory-reared specimens. The eggs, measuring 2.1–2.4 mm in diameter, were demersal, almost spherical
in shape, transparent and unpigmented, with a pale yellow yolk without oil globules. Hatching occurred 39–45 h after fertilization
at 26.8°–27.4°C. The newly hatched larvae, measuring 4.8–5.1 mm in body length (BL) with 22 + 17 = 39 myomeres, were characterized
by melanophores already deposited on the eyes. The eggs of B. canarensis resembled those of the related danionin species Candidia barbatus, Opsariichthys uncirostris uncirostris, Zacco platypus, Z. sieboldii, and Z. temminckii. Although the larvae of B. canarensis were also similar to those of the foregoing species in general morphology, they differed in having a straight notochord tip
and pigmentation on the eyes at hatching and the almost entire absence of melanophores on the ventral body surface from the
yolk sac to postflexion larval stages. Conversely, melanophores occurred on the anterior abdominal and pericardial cavities
from the preflexion to postflexion larval stages. 相似文献
7.
Two larvae [17.4 mm standard length: SL (postflexion stage)] and 26.1 mm SL (transformation stage)] and a juvenile (31.7 mm
SL) of a phosichthyid, Polymetme elongata, from Suruga Bay and offshore waters, central Japan, are described. These specimens had an elongate body with relatively
short preanal length (53–63% SL), long anal fin base (2.6–3.4 times dorsal fin base length), and anal fin origin below dorsal
fin base, and were further characterized by a blackish flap on each eye and internal clusters of melanophores (e.g., along
caudal myosepta around midlateral line and on ventral margin of caudal peduncle). The short preanal length and larval melanophore
pattern were very similar to those of another phosichthyid, Yarrella blackfordi, from the Atlantic Ocean. 相似文献
8.
Atsushi Fukui Miyuki Suzuki Yachiyo Suzuki Itsuro Uotani 《Ichthyological Research》2002,49(2):159-164
The early ontogeny of Lophonectes gallus (Bothidae) is described based on 83 specimens (1.9–17.5 mm BL), collected from the Tasman Sea off southeastern Australia.
The larvae are diagnosed by the following array of characters: vertebrae 10 + 30–31 = 40–41; one elongated dorsal fin ray
and several melanophores present on gut in preflexion stage (1.9–4.7 mm BL); and spines on posterior basipterygial process,
and urohyal, cleithrum, and epiotic without spines after postflexion stage (8.0–17.5 mm BL). The larvae are relatively small
at metamorphosis (15–18 mm BL) compared with other bothid larvae.
Received: March 22, 2001 / Revised: December 12, 2001 / Accepted: December 26, 2001 相似文献
9.
Embryonic, larval, and juvenile development of an Indian cyprinid fish, Chela dadiburjori, is described from laboratory-reared specimens. The eggs, measuring 0.7–0.9mm in diameter, were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule. Hatching occurred 50–61h after fertilization at ca. 27°C. The newly hatched larvae, measuring 2.4–2.6mm in body length (BL), had melanophores on the body with 14–16+14–17=29–31 myomeres. Two dark transverse bands on the ventral body surface and one melanophore on the lower margin of the eye in newly hatched larvae were diagnostic. Additionally, a cement organ for adhering to objects was present on the forehead of yolk sac larvae <3.1mm BL. The yolk was completely absorbed at 3.5mm BL. Notochord flexion was initiated at 5.0mm BL and finished at 6.0mm BL. Aggregate numbers of all fin rays were completed at 9.2mm BL. Squamation was initiated on the caudal peduncle at 8.0mm BL and completed at 10mm BL. The eggs of C. dadiburjori resembled those of the closely related species Devario malabaricus and Danio rerio. The larvae and juveniles of C. dadiburjori were also similar to those of the latter species in general morphology, especially the presence of body melanophores in newly hatched individuals and a distinctive lateral streak on the head during the period from yolk sac to postflexion larvae. However, early yolk sac larvae of C. dadiburjori were more similar to those of Devario malabaricus than Danio rerio in having a cement organ on the forehead. Larvae and juveniles of C. dadiburjori differed from those of the latter two species in pigmentation on the ventral body surface at hatching and around the mouth during the period from preflexion to early postflexion larvae and in having a dark lateral streak or band on the body in postflexion larvae and juveniles. 相似文献
10.
Embryonic, larval, and juvenile development of two cyprinid species belonging to the Zacco temminckii species' group, Z. temminckii (Temminck and Schlegel) and Zacco sp. (type A), are described and compared with each other from laboratory-reared and wild specimens. The eggs of both species
were closely similar except in diameter [1.92–2.20 mm in Z. temminckii vs. 1.60–1.75 mm in Z. sp. (type A)], being demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk, and no oil
globule. Hatching occurred 40–53 h after fertilization in Z. temminckii and after 47–60 h in Z. sp. (type A). The newly hatched larvae of both species [4.9–5.3 mm in body length (BL) in Z. temminckii and 3.5–4.8 mm BL in Z. sp. (type A)] also resembled each other, having a large transparent pear-shaped yolk and lacking body pigmentation. Myomere
counts of Z. temminckii and Z. sp. (type A) larvae and juveniles were 24–27 + 14–17 = 41–42 and 23–27 + 14–17 = 40–41, respectively. The yolk was completely
absorbed at 8.3 mm BL in Z. temminckii and at 6.6 mm BL in Z. sp. (type A). Notochord flexion was initiated and completed at 7.8 mm BL and 8.2 mm BL in Z. temminckii and at 6.3 mm BL and 6.6 mm BL in Z. sp. (type A), respectively. Aggregate numbers of all fin rays were completed at 17 mm BL in Z. temminckii and 13 mm BL in Z. sp. (type A). Although the morphology of larvae and juveniles of both species was very similar, differences in body length
of each developmental stage, the duration and process of disappearance of the adipose finfold, the anal fin ray counts, and
pigmentation on the lateral body surface were clearly recognized.
Received: August 10, 2001 / Revised: March 14, 2002 / Accepted: March 27, 2002 相似文献
11.
Shinsuke Morioka Sayaka Ito Shoji Kitamura Bounsong Vongvichith 《Ichthyological Research》2009,56(2):162-171
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
12.
Recruitment courses of three amphidromous sleeper species, Eleotris acanthopoma, E. melanosoma, and E. fusca, were investigated at the surf zone adjacent to the river mouth and at five stations in the Teima River on Okinawa Island,
Japan. All three species occurred at the surf zone as pelagic larvae with transparent and compressed body, a conspicuous air
bladder, and an emarginated caudal fin. Eleotris fusca (16.0–19.6 mm in standard length: SL) sometimes possessed a vestige of the larval chin barbel and were larger than E. acanthopoma (9.7–13.2 mm SL) and E. melanosoma (11.2–12.8 mm SL). The pelagic larvae were also collected during full tide from the lower reaches of the tidally influenced
area of the river. The pelagic larvae may be carried in and out of the estuary with some tidal fluxes, and they may settle
when they reach the upper tidally influenced area where the salinity becomes extremely low. Body width and pigmentation of
newly settled larvae increased. E. fusca was considered to migrate upstream to the freshwater area against the flow of the river just after reaching the settled stage.
After settlement, all three species became completely pigmented, the caudal fin became round in shape, and the fin ray counts
became complete with growth. Also, E. acanthopoma dispersed widely to the lower part of the tidally influenced area or to the lower reaches of the freshwater area, E. melanosoma dispersed to the lower part of the tidally influenced area, and E. fusca dispersed upstream. 相似文献
13.
Ovarian maturation of the pufferTakifugu exascurus (Jordan et Snyder) was induced, and embryonic, larval and juvenile development was observed. The brood fish were collected
in Tassha Bay, Sado Island (38°05′N, 138°15′E), during the spawning season in 1986 which seemed to extend from late June to
mid-July. To each female 3 mg acetone-dried pituitary ofHypophthalmichthys molitrix was injected to induce ovarian maturation, which took place in about 77 hours at a water temperature of 19.5–21.0°C. The
eggs obtained by hormone injection were artificially fertilized with the milt from a collected male. The hatched larvae were
fed successively on rotifersBrachionus plicatilis, Artemia nauplii and minced fish meat, and reared for a period of about one year.
The eggs were spherical, 1.24±0.04mm in diameter, demersal and adhesive. The egg-membrane Was transparent and yolk was orange
in color, containing a cluster of small oil-globules. The incubation period was about 160 hours at a water temperature of
18.5–21.0°C. The newly-hatched larvae, measuring 2.9– 3.1 mm TL, had 8+15 = 23 myomeres. Absorption of the yolk was completed
3 days after hatching, by which time the larvae had attained 3.5–3.6 mm TL. Larval finfolds disappeared and rudimentary dorsal,
anal and caudal fins formed at 4.1–4.4 mm TL, in 6 days after hatching. In 9-day old larva (5.4 mm TL), fin ray rudiments
appeared on the dosai, anal and caudal fins and spine-like scale formed on the belly. In 16-day old specimens, 9.1–10.2 mm
TL, the full complements of fin rays were completed on all the fins and the fish reached the juvenile stage. The growth of
larvae and juveniles reared in 1986–1987 is expressed by the following equations, where y is total length (mm) and x is days
after hatching. y1 = 2.9420· 1.0639x 0 ≦ x ≦ 19 (r = 0.998) y2 = 4.0286· 1.0464x 19≦ x ≦ 33 (r = 0.998) y3 = 9.8854· 1.0180x 33 ≦ x ≦ 72 (r = 0.996) y4 = 20.1555· 1.0080x 72 ≦ x ≦ 115 (r = 0.998) y5 = 28.0610· 1.0049x 115 ≦ x ≦ 202 (r = 0.995) 相似文献
14.
Embryonic, larval, and juvenile development of a Taiwanese cyprinid fish, Candidia barbatus, is described from laboratory-reared specimens. The eggs, measuring 1.8–2.1 mm in diameter, were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule. Hatching occurred 56–69 h after fertilization, the newly hatched larvae measuring 4.9–5.3 mm in body length (BL) with 25–26 + 13–14 = 39–40 myomeres. The yolk was completely absorbed at 7.6 mm BL. Notochord flexion was initiated at 6.8 mm BL and finished at 7.6 mm BL. Aggregate numbers of all fin rays were completed at 12 mm BL. Barbels on the upper jaw appeared near the corner of the mouth at 17 mm BL. Eggs of the species closely resembled those of its related cyprinid genera, Opsariichthys and Zacco. Larvae and juveniles of C. barbatus were similar to those of O. uncirostris subspp., Z. platypus, and Z. pachycephalus, but differed from the latter in the process of disappearance of the adipose finfold (postflexion larval stage), barbels on upper jaw (juvenile stage), and pigmentation on the lateral body surface (postflexion larval and juvenile stages). Although C. barbatus also differed from the Z. temminckii species' group [Z. temminckii and Zacco sp. (sensu Hosoya, 2002)] in having barbels, larvae and juveniles of the former showed more similarity to the latter species group than to O. uncirostris subspp., Z. platypus, and Z. pachycephalus, from the aspect of head and body pigmentation. 相似文献
15.
Morphological development, including that of fins, labyrinth organ, body proportions, and pigmentation, in laboratory-hatched
larval and juvenile snakeskin gourami Trichogaster pectoralis is described. Body lengths (BL; mean ± SD) of larvae and juveniles were 2.3 ± 0.1 mm just after hatching (day 0) and 8.2 ± 0.6 mm
on day 22, reaching 14.1 ± 2.3 mm on day 48. Aggregate fin ray numbers attained their full complements in juveniles >11.8 mm
BL. Preflexion larvae started feeding on day 2 following upper and lower jaw formation, the yolk being completely absorbed
by day 12. Subsequently, oblong conical teeth appeared in postflexion larvae >8.2 mm BL (day 16). Melanophores on the body
increased with growth, with a large dark spot developing on the lateral midline at the caudal margin of the body in flexion
larvae >6.1 mm BL. Subsequently, a broad vertical dark band from the eye to the caudal peduncle developed in postflexion larvae
>8.9 mm BL. Proportions of head and pre-anal lengths became constant in postflexion larvae greater than ca. 9–10 mm BL, whereas
those of maximum body depth, eye diameter, and snout length failed to stabilize in fish of the size examined in this study.
First soft fin ray of the pelvic fin elongated, reaching over 40% BL. The labyrinth organ differentiated in postflexion larvae
>7.4 mm BL (day 22). Comparisons of larval and juvenile morphology with another anabantoid species Anabas testudineus were also made, revealing several distinct differences, particularly in the numbers of myomeres and fin rays in the dorsal/anal
fins, mouth location and body shape. 相似文献
16.
Shinsuke Morioka Phonaphet Chanthasone Phoutsamone Phommachan Bounsong Vongvichith 《Ichthyological Research》2012,59(1):53-62
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
17.
Makoto Okamoto Keiichi Takeda Hiroya Sugisaki Takashi Asahida 《Ichthyological Research》2007,54(1):61-67
The early life stages of Lestidiops sphyraenopsis (Paralepididae) are described on the basis of 14 specimens [7.8 mm in notochord length (NL)–88.6 mm in standard length (SL)]
collected from the western North Pacific, and the holotype of Stemonosudis molesta is reexamined. Larval L. sphyraenopsis occurred in the Kuroshio waters, and juveniles were taken in the Kuroshio–Oyashio transition waters. Diagnostic characters
of larval and juvenile L. sphyraenopsis are 96–101 myomeres; 27–31 anal fin rays; 4–9 peritoneal pigment sections in larvae (7.8 mm NL–27.3 mm SL); dorsal and anal
pigment patches present; and anus located anterior to a vertical through dorsal fin origin. Stemonosudis molesta, known only from the holotype from the South Pacific, is similar to immature specimens of L. sphyraenopsis, but can be clearly distinguished from the latter by having higher vertebral counts (105 vs. 96–101) and by morphometric
and pigment differences. Consequently, S. molesta is a valid species, and the distribution of L. sphyraenopsis is restricted to the North Pacific. 相似文献
18.
Embryonic, larval and juvenile development of the cottid fish,Pseudoblennius percoides were described on the basis of a series of laboratory-reared specimens. The eggs were demersal, adhesive, almost spherical
in shape, measuring 1.66–1.82 mm in diameter, and with numerous various-sized oil globules. Neighboring eggs adhered to each
other to form an egg mass. Hatching occurred between 13 and 16 days after spawning at a water temperature of 15.4 to I6.5°C.
Newly hatched larvae measured from 6.5 to 7.3 mm, averaging 6.9 mm TL, and possessed 40 myomeres. Absorption of the yolk was
completed at about 7.5 mm TL. Flexion of the notochord started and finished at about l0 mm TL and about 14 mm TL, respectively.
Aggregate numbers of all fin rays were completed at over 16 mm TL, when the larvae reached the juvenile stage. The pigment
pattern became the same as that of adults in juveniles longer than 25 mm TL. Lateral lines were completed at over 44 mm TL,
when the juveniles attained to the young stage. The early stages of this species were clearly distinguished from those ofP. cottoides, and the juveniles of fourPseudoblennius species, i.e.P. percoides, P. cottoides, P. marmoratus andP. zonostigma, could be identified mainly by their pigment patterns. 相似文献
19.
Anirban Chakraborty Martien J.P. van Oijen Kelvin K.P. Lim Yukio Iwatsuki 《Ichthyological Research》2006,53(1):41-46
A trichiurid, Lepturacanthus roelandti (Bleeker, 1860), previously regarded as a synonym of L. savala (Cuvier, 1829), is redescribed as a valid species on the basis of the holotype of the former and four non-type specimens.
This species differs from the two valid congeners, viz., L. savala and L. pantului (Gupta, 1966), in having a gold sheen or yellowish-silver color when fresh (vs. steel-blue with metallic sheen in the latter
two), posterior margin of maxilla reaching or extending beyond a vertical through hind eye margin (vs. not extending beyond
a vertical through hind eye margin), pectoral fin slightly longer than snout (vs. slightly shorter than snout), tip of pectoral
fin clearly extending beyond dorsal outline when vertically orientated (vs. not reaching dorsal outline), gill rakers absent
or reduced to stiff ossified structures (vs. well developed, spinelike), first anal fin spine situated below the 40th–43rd
dorsal fin ray (vs. below 35th–39th in L. pantului and 35th–40th in L. savala), precaudal vertebrae 42–43 (vs. 35–39 in L. pantului and 36–40 in L. savala), and attaining larger sizes [882–1200 mm in total length (TL) vs. less than 800 mm TL in the latter two]. 相似文献
20.
The embryonic and larval development ofCobitis takatsuensis, a mountain stream spinous loach, was surveyed by incubating artificially inseminated eggs. The mean diameter of the inflated
eggs and mean total length of newly-hatched larvae were 2.7 mm and 5.7 mm, respectively. The eggs were spherical, transparent
and unpigmented, with a pale yellow yolk and no oil globule. The daily cumulative temperature to hatching was estimated to
be 70–110°C. day. Hatched larvae were unpigmented with outer gill filaments on their cheeks, as in otherCobitis species, but the melanophores were comparatively less obvious at each developmental stage. The larvae started feeding eleven
days after hatching yolk absorption being completed sixteen days after hatching. All the fin rays were fully developed and
the juvenile stage reached at 16 mm TL, 38 days after hatching. Embryonic and larval developmental traits ofC. takatsuensis, such as egg size, clutch size and larval pigmentation, were similar to the Korean species,Niwaella multifasciata, that lives in the upper reaches of the Nak-tong river, andN. delicata, which inhabits Japanese mountain streams, rather than to its congeners. Among cobitine fishes, the spawning of a small number
of larger eggs yielding larger larvae without pigmentation, characteristics shared byC. takatsuensis, N. multifasciata andN. delicata, is attributable to adaptation to cold mountain streams. 相似文献