Developmental morphology of the cyprinid fish Tanichthys albonubes

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.     

Developmental morphology of the cyprinid fish Chela dadiburjori

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.     

Developmental morphology of the cyprinid fish Horadandia atukorali

Embryonic, larval, and juvenile development of a small Indian cyprinid, Horadandia atukorali, is described from laboratory-reared specimens. The eggs, measuring 0.7–0.8mm in diameter, were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk without oil globules. Hatching occurred 47–54h after fertilization at 26.3–27.5°C. The newly hatched larvae, measuring 2.3–2.6mm in body length (BL) with 16+13=29 myomeres, had no melanophores, except on the eye, a single melanophore occurring on the lower margin, and xanthophores surrounding the pupil. The yolk was completely absorbed at 3.0mm BL. Notochord flexion was initiated at 4.0mm BL and finished at 4.4mm BL. Aggregate numbers of all fin rays were completed at 8.0mm BL. Squamation was initiated at 6.4mm BL and completed at 9.5mm BL. Although the eggs of Horadandia atukorali resembled those of other small danionin species, including Aphyocypris chinensis, Chela dadiburjori, Danio rerio, Devario malabaricus, and Hemigrammocypris rasborella, they differed from those of Danio rerio and Devario malabaricus in having a narrower perivitelline space. The larvae and juveniles of Horadandia atukorali were also similar to those of the latter five species in general morphology, especially in the presence of a melanophore on the lower margin of the eye at hatching, as in C. dadiburjori. However, the early life stage morphology of Horadandia atukorali differed from the other danionin species in having a conical yolk sac at hatching, no cement organ on the forehead in the yolk-sac larval stage, a divided gas bladder in the flexion larval stage, two dark lateral streaks on the head and chevron-like melanophores on the ventral body surface from the preflexion to postflexion larval stages, and xanthophores on the eyes at hatching.     

Developmental morphology of the Indian cyprinid fish Barilius canarensis

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.     

Segmentation and fusion on the midline: Basibranchial homologies in cypriniform fishes

The development and homologies of the median elements of the ventral hyoid and branchial arches of Cypriniformes have been unclear. We compared the developmental morphology of this region across five species (Cycleptus elongatus, Luxilus zonatus, Danio rerio, Devario auropurpureus, and Cobitis striata), representing three of five major clades of cypriniforms. The development of basibranchial 1 is similar in catostomids and cyprinids, where a single, elongate, basihyal + anterior copula divides into separate elements. A gap develops between the posterior end of the basihyal cartilage and the anterior copula in catostomids but in cyprinids (Luxiluszonatus, Danio rerio, and Devarioauropurpureus) there is little separation and the basihyal and basibranchial 1 may grow close together or retain a cartilaginous connection (Danio rerio, several outgroups). In loaches and Gyrinocheilus, the gap posterior to the basihyal has been alternately interpreted as either the absence or posterior displacement of basibranchial 1. Uniquely among examined species, in Cobitis striata, the basihyal cartilage and anterior copula form as separate cartilages and remain distinct throughout development with a prominent gap between the basihyal and most anterior basibranchial, which we interpret as loss of basibranchial 1. In the posterior region associated with branchial arches 4 and 5, all examined species except Danio rerio, which has only a basibranchial 4 cartilage, have separate basibranchial 4 and 5 cartilages in early ontogeny. Basibranchials 4 and 5 remain separate in Cycleptus elongatus, Devario auropurpurea, and Cobitis striata, but fuse in Luxilus zonatus to form a posterior copula. The orientation of basibranchial 4 and 5 cartilages in Cobitis striata is similar to catostomids and cyprinids. The most posterior median element in the branchial arches, the post‐ceratobranchial cartilage, generally forms as a separate cartilage in catostomids but in Cobitis striata is connected with basibranchial 5 cartilage from earliest appearance. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

Larval development of Pseudorhombus oculocirris and P. arsius (Pleuronectiformes, Paralichthyidae) from off southern Japan

 Larvae of two paralichthyids, Pseudorhombus oculocirris and P. arsius, are described and illustrated from specimens collected off Tosa Bay, southern Japan. Peudorhombus oculocirris larvae (5 specimens, 4.5–7.8 mm BL) are characteristic in having 6 or 7 elongated anterior dorsal fin rays and poorly developed head spines and melanophores on the tail. Pseudorhombus arsius larvae (3 specimens, 5.3–8.4 mm BL) are distinctive in having 11 or 12 elongated anterior dorsal fin rays and well-developed head spines, including a row of spines on the sphenotic. Received: June 28, 2001 / Revised: November 2, 2001 / Accepted: November 22, 2001     

Descriptive morphology of the eggs,larvae, and juveniles of two cyprinid fishes belonging to the <Emphasis Type="Italic">Zacco temminckii</Emphasis> species' group

 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     

Developmental morphology of the cyprinid fish, Candidia barbatus

 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.     

The eggs and larvae of the giant mudskipper, <Emphasis Type="Italic">Periophthalmodon schlosseri</Emphasis>, collected from a mudflat in Penang,Malaysia

 Eggs of the giant mudskipper, Periophthalmodon schlosseri were collected from a burrow in Penang, Malaysia, in November 1998, and hatched larvae were reared in the laboratory. The eggs were demersal with adhesive filaments and elliptical in shape (0.83–1.43 mm in long-axis diameter). Newly hatched larvae (2.1–2.6 mm in notochord length) possessed a yolk sac. The number of myomeres was 10 + 17 = 27. The mouth and anus were already opened. The larvae started feeding one day after hatching and completely absorbed the yolk by the third day at a water temperature of 24.5–28.0°C. Received: April 9, 2002 / Revised: October 25, 2002 / Accepted: December 10, 2002     

Early ontogeny of Lophonectes gallus (Bothidae) from southeastern Australia

 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     

Eggs and larvae of <Emphasis Type="Italic">Awaous melanocephalus</Emphasis> (Teleostei: Gobiidae)

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.     

Larval and juvenile development of <Emphasis Type="Italic">Lestidiops sphyraenopsis</Emphasis> Hubbs, 1916 (Aulopiformes: Paralepididae) in the western North Pacific,with a reexamination of the holotype of <Emphasis Type="Italic">Stemonosudis molesta</Emphasis> (Marshall, 1955)

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.     

Ontogenetic diet shift, feeding rhythm, and daily ration of juvenile yellowfin goby Acanthogobius flavimanus on a tidal mudflat in the Tama River estuary, central Japan

To ascertain the feeding habits of benthic juvenile yellowfin goby Acanthogobius flavimanus, the gut contents of 599 specimens (15–41 mm in standard length, SL), collected on a tidal mudflat in the Tama River estuary throughout the diel cycle, were examined. The major prey items changed from harpacticoid copepods to errant and sedentary polychaetes at ca. 20 mm SL. Prey width increased with fish size. Fish of 26–28 mm SL fed mainly from sunset to morning, with highest feeding intensity during twilight hours and/or high tide. Based on the gut evacuation rate estimated from a forced feeding experiment in the laboratory and data for the diel change of mean gut-content volume in the field, the daily ration of juvenile yellowfin goby (26–28 mm SL) was calculated to be 13.8 mm³ fish⁻¹ day⁻¹. This volume is approximately equivalent to 3.9 individuals of the errant polychaete Ceratonereis erythraeensis (9.7 mm in body length, BL) or 8.1 individuals of the sedentary polychaete Prionospio japonica (14.8 mm BL), both species occurring abundantly on the mudflat during the study.     

Occurrence of Ayu (<Emphasis Type="Italic">Plecoglossus altivelis</Emphasis>) larvae in northern Vietnam

The early life history of Ayu (Plecoglossus altivelis) was investigated in the Kalong and Tien Yen River systems, northern Vietnam, which is probably the most southern distribution locality for this species, during the period of November 2010 to February 2011. A total of 248 larvae were captured in the Kalong, and none were collected in the Tien Yen. There was little difference in development between the Kalong larvae and those of P. a. altivelis and P. a. ryukyuensis. Temperatures and salinities when the larvae were collected ranged from ca. 12 to 21°C and from ca. 3.5 to 30 psu. The preflexion to flexion larvae (primarily preflexion with yolk, 5.2–12.9 mm BL) occurred in the central current from December to February, with a peak abundance in early January. The flexion to postflexion (primarily postflexion, 14.1–23.8 mm BL) larvae occurred in the bank waters from early January to late February. The larval occurrence in the Kalong was 1–2 months later than for P. a. altivelis in Japan and P. a. ryukyuensis in the Ryukyu Islands, probably because of the delay until a reasonable photoperiod for the start of spawning in the lower latitudinal region. The larvae were never collected from the sea, where the temperatures were lower than in the river and estuary in January and February, unlike in Japan.     

Larval development of bigmouth manefish Caristius macropus (Perciformes: Caristiidae) from the western North Pacific

Larvae of bigmouth manefish Caristius macropus are described and illustrated on the basis of seven specimens (4.2–10.5 mm in body length) from the Kuroshio waters (0–60 m depth) and the transition waters (surface) between the Kuroshio and Oyashio fronts of the western North Pacific. The present larvae of C. macropus are distinguished from those of Paracaristius maderensis that inhabit the North Pacific by having 39–40 myomeres, 34 dorsal-fin rays, and 22 anal-fin rays. The present study, along with previous studies of the early life stages of caristiids, shows that larvae of the family may be defined by the following characters: body elongate in preflexion stage but becoming deep bodied and hatchet shaped after notochord flexion; anus located near vertical through base of pectoral fin; head large, without spination or serration; a distinct vertical band on the posterior tail throughout the larval stages, and two bands gradually appearing on the tail and trunk during the flexion and postflexion stages; and melanophores present around the notochord tip by the flexion stage. Adult C. macropus are found in the subarctic and temperate waters of the North Pacific; however, the present study and other occurrences of early life stages of the species probably indicate that C. macropus may spawn over a wide area in the North Pacific.     

Early life history of kitsune-mebaru,sebastes vulpes (scorpaenidae), in the sea of japan

The larval and juvenile stages of kitsune-mebaru,Sebastes vulpes, based on 50 wild specimens collected in, the Sea of Japan, are described and illustrated, and some ecological aspects of the early life history (feeding, horizonal distribution and habitat shift) included. Preflexion larvae became extruded between 3.9–4.6 mm body length (BL) and notochord flexion occurred between 4.7–7.1 mm BL. Transformation from postflexion larvae to pelagic juventiles occurred between 13–17 mm BL. Compared with other rockfish species,S. vulpes is deep-bodied, throughout both larval and, juvenile stages. Larval and juvenileS. vulpes inhabit mainly coastal water surface layer (usually on the continental shelf), but do not occur offshore region (northwest of Oki Islands). Although someS. vulpes juveniles are associated with drifting seaweed, such clumps are not indispensable habitats for any stages. Surface-to-benthie migration of juveniles occurs at about 25 mm BL. Preflexion and flexion larvae feed mainly on copepod nauplii, and postflexion, transforming larvae and pelagic juveniles mainly on calanoid copepodites (Parracalanus parvus).     

Early life history of mebaru,sebastes inermis (scorpaenidae), in sendai bay, japan

The early life history of the viviparous scorpaenid,Sebastes inermis, in Sendai Bay, Japan, was studied and early development described. Newborn preflexion larvae ofS. inermis were about 5.2 mm BL. Notochord flexion occurred at 5.4–8.0 mm BL and transformation at 14–20 mm BL. Preflexion and flexion larvae ofS. inermis were distinguished from similar larvae by the pigmentation pattern along the dorsal and ventral midlines of the tail. Pigmentation inS. inermis was light throughout the larval and early juvenile periods. Planktonic larvae were particularly abundant in coastal waters of Sendai Bay but not offshore. Vertical and horizontal larval sampling indicated that early larvae occupied near surface waters and horizontal larval sampling indicated that early larvae shift to a benthic habitat occurred at about 12 mm BL, at the end of the postflexion larval period.Sebastes inermis do not have a distinct pelagic juvenile stage, unlike many North Pacific species ofSebastes.     

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.     

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. Newly-hatched larvae swam just below the surface in the aquaria. Preflexion larvae (8.9–9.5 mm BL), in which the oil globule had disappeared, swam in the middle layer, while juveniles (13.8–15.8 mm BL) began swimming on the bottom of the aquaria. Swimming behavior observed in the aquaria suggested that the fish started to change to a demersal existence at the juvenile stage.     

Reproductive biology and morphology of eggs and larvae of Stiphodon percnopterygionus (Gobiidae: Sicydiinae) collected from Okinawa Island

Reproductive biology and morphology of eggs and early larvae of the sicydiine goby Stiphodon percnopterygionus were investigated on Okinawa Island, southern Japan. Spawning season was estimated as being from May to December. Standard length at maturity was approximately 20 mm in both sexes, and batch fecundity was approximately 1000–10 000 per female. The egg masses, guarded by the male, were laid on the undersurface of stones in freshwater. The pyriform eggs had long- and short-axis diameters of 0.54–0.58 mm and 0.49–0.50 mm, respectively. Newly hatched larvae (1.20–1.32 mm notochord length: NL) were poorly developed, with large yolk sacs and unopened mouths. Three days after hatching (1.87–2.05 mm NL), eyes were fully pigmented and mouths were opened. An erratum to this article is available at .