Development of the gonads in Channa punctatus Bloch (Osteichthyes: Channidae)

The history of the germ cells is traced from the time of hatching. The germ cells are larger in size and have faintly staining cytoplasm, clear cell outline and a distinct nucleus. They migrate by ameboid movement to reach the genital ridge and aggregate to lie against the gonadal epithelium prior to the formation of gonads. The germ cells are distributed along the gonad primordia. The period of sex differentiation occurs between the 5.4 mm to 12 mm stage. The testis formation is recognized by the presence of germ cell nests and the sperm duct cord. The formation of the ovary is noted by the enlargement of the germ cells of uniform size and the development of the ovarian cavity. The ovaries are described in four stages ranging from 21 mm to 135 mm fish. At 21 mm stage the ovarian cavity is continuous but is obliterated at 35 mm stage due to the projection of the ovigerous lamellae. The common opening for both the ovaries develops at 35 mm stage. The testes are described in four stages ranging from 23 mm to 135 mm fish. They differentiate more slowly and the first maturation division is seen at 90 mm stage.     

Fishery of the Deep-water Rose Shrimp Parapenaeus longirostris (Lucas, 1846) (Crustacea: Decapoda) in the Northern Tyrrhenian Sea (Western Mediterranean)

The aim of this study is to provide information on the fishing pattern of Parapenaeus longirostris in the northern Tyrrhenian Sea (western Mediterranean), in order to improve the management of the resource in the area. Data were obtained from commercial fishery, covering the period 1991–2002. Catch rates revealed notable inter-annual fluctuation of the P. longirostris landing, probably due to the life cycle of the species. The highest yields (kg per hour of trawl) of the commercial fishery were obtained at depths ranging between 180 and 300 m, the lower ones at depths between 100 and 180 m, where small specimens are more abundant. Commercial catches were characterised by a very low presence of specimens smaller than 20 mm carapace length (CL), mainly due to the deeper localisation of the fishing grounds when compared to the recruitment areas of the species. The size at which 50% of the specimens were discarded by the fishermen was 15 mm CL, while the estimated size at first capture of the individuals caught by the commercial net was 12.4 mm CL.     

Growth and breeding of Spirorbis rupestris (Polychaeta: Serpulidae)

Settlement of young occurred mostly between June and September. Monthly increments in coil diameter of tubes were about 0.5 to 0.7 mm between September and January, but only about 0.2 mm between January and March. Growth seems to continue throughout life, which lasts for about a year. Breeding may begin at a coil diameter of about 2 mm, but is more prolific in larger individuals. Maturation of gametes occurred slowly at 5C, more rapidly at higher temperatures. Spawning occurs between March and October, particularly between April and September. Incubation lasts for much more than a fortnight and there was no trace of the neap tide breeding rhythm seen in closely related species.     

Growth and morphological development of larval and juvenileepinephelus bruneus (perciformes: Serranidae)

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.     

Burrows of Paragnathia (Crustacea: Isopoda) and bledius (Arthropoda: Staphylinidae) Enhance cliff erosion

In coastal cliffs consisting of Pliocene fine‐grained clastic sediments at El Rompido, Huelva, Spain we discovered around the high water line an extensive zone of about 1.5 m in height burrows that were made by up to 4 mm long isopods Paragnathia formica (Hesse) and small 5 mm long staphylinid beetles (Bledius cf. corniger Rosenhauer). The burrowing zone was crowded with irregular burrows 2–5 mm in diameter and extended some 5 cm deep in the cliff. The base of the cliff showed a clear (bio)erosional notch due to this burrowing activity, comparable to those produced by marine boring and scraping organisms in, for example, calcareous rocks. This indicates that the activity of Paragnathia and Bledius helps in eroding the cliffs, a phenomenon not published earlier as far as we know. A comparable but less extensive burrowed zone was found farther upstream near Cartaya. Their presence around the high tide zone also might prove these burrows to be good markers of former high tide lines in older cliffs.     

Juvenile development of a flathead,Suggrundus meerdervoortii (Scorpaeniformes: Platycephalidae)

Juvenile development ofSuggrundus meerdervoortii was described, based on twelve specimens (12.9–43.8 mm SL) collected from off Yamagata Prefecture, Japan Sea. Two exterior openings in the lateral line scales were completed at ca. 35 mm SL, with the interopercular flap and iris lappet being visible at ca. 44 mm SL, these all being useful taxonomic characters. In juveniles and additional young and adult specimens (ca. 70–191 mm SL), the proportions of head length, snout length, orbital diameter, caudal peduncle depth and caudal fin length decreased with growth; interorbital width decreased rapidly until ca. 70 mm SL, but more or less stabilised thereafter (70–191 mm SL).     

Biology of Bactrocera (Zeugodacus) tau (Walker) (Diptera: Tephritidae)

The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.     

Laboratory studies of factors affecting egg hatch of triops longicaudatus (LeConte) (Notostraca : Triopsidae)

Egg hatch was greatest (78.33%) for eggs not previously desiccated. A reduction in numbers hatched occurred as the relative humidity at which they were dried decreased. Some eggs hatched (0.67–79.33%) at pH levels of 3.10–10.01 with the highest hatch at pH 5.60. Water temperature greatly affected egg hatch. No hatch occurred until temperatures were above 14°C. A constant 29°C significantly inhibited hatching. Egg hatch increased 13.00 to 43.42% as salinity decreased from 2200 to 9.24 micromhos/cm. As little as 13 mm of flooded soil covering the eggs prevented them from hatching for 14 days. Eighteen percent hatch resulted when soil and eggs were redistributed to a 1 mm soil layer. Egg samples from the same parent, even though treated similarly, often hatched at greatly varying rates and only rarely was hatching 100% within a replication.     

Early ontogeny of the big roughy Gephyroberyx japonicus (Beryciformes: Trachichthyidae) in captivity

Development of eggs and larvae of the big roughy Gephyroberyx japonicus are described on the basis of specimens reared in captivity. Spherical eggs (diameter 1.26–1.35?mm) with a single oil globule were pelagic. Newly hatched larvae (2.8–3.1?mm in body length, BL) had strong linear pigmentation on the head and trunk. The mouth opened at ca. 3.5?mm BL; thereafter the yolk was absorbed. Notochord flexion started at ca. 4.5?mm BL when body depth increased rapidly, and melanophores spread to all of the body. Notochord flexion was completed at ca. 5.0?mm BL. Head spination and pelvic fins began to develop during the flexion stage.     

Prenatal development of the integument in Delphinidae (Cetacea: Odontoceti)

The prenatal development of epidermis, dermis, and hypodermis was studied in embryos of different ago of two delphinid species (Stenella attenuata, Delphinus delphis), using light and transmission electron microscopical methods. The delphinid embryo is covered by a multilayered tissue formed by four different epidermal generations (periderm, stratum intermedium-I, str. intermedium-II, str. spinosum) produced by the str. basale. The first layer appears at about 40–50 mm of body length, the second type (s.i.-I) about 60–160 mm, and the third type (s.i.-II) is present at 160–500 mm. The first spinosal cells are produced at 225–260 mm body length; thenceforth, the epidermis increases continuously in thickness. Epidermal ridge formation begins about 400–mm body length. The development of the dermis is characterized by the early production of thin connective tissue fibers (40- 70-mm body length) and simultaneously the cutaneuous muscle matures in structure. Vascular development intensifies between embryos of 150–225 mm, and collagen production increases markedly in fetuses of 225–260-mm length. These events are paralledled by an increase in dermal thickness. The first elastic fibers can be recognized in the skin from the abdomen at about 600-mm body length. The development of the hypodermis is marked by very rapid and constantly progressing growth, beginning about 60-mm body length. The first typical fat cells appear in animals of 360–400 mm. Regional differences are obvious for all skin layers with regard to the flippers, where structural maturation proceeds more rapidly than in dorsal or abdominal regions. © 1995 Wiley-Liss, Inc.     

PREDATOR-PREY INTERACTIONS BETWEEN LEPSIELLA (BEDEVA) PAIVAE (GASTROPODA: MURICIDAE) AND KATELYSIA SCALARINA (BIVALVIA: VENERIDAE) IN PRINCESS ROYAL HARBOUR, WESTERN AUSTRALIA

On a sandy beach at Shoal Bay in Princess Royal Harbour, Albany,southwestern Western Australia, lives a small muricid gastropodthat feeds virtually monotonically on the overwhelmingly dominantresident bivalve Katelysia scalarina. Lepsiella paivae livesburied in the sand and attacks its prey within it. Because ofits small size (<13 mm shell height), bivalve prey isalso small and this study demonstrates a preference for K. scalarinaof 5 mm shell length, i.e. juveniles. Laboratory experimentsalso suggested a possible preference for attack of the rightvalve. Lepsiella paivae can and does, however, attack largerprey (up to 15 mm shell length), but cannot consume themcompletely. A second visit to Princess Royal Harbour in theAustral winter, when there was no juvenile K. scalarina present,showed L. paivae to be attacking at the sand surface, also bydrilling, the small (<4 mm) gastropod Hydrococcus brazieri(Hydrococcidae). SEM studies of experimentally determined drillholes of L. paivae show them to be of variable form, some straightsided, others bevelled (like a naticid) and <500 µmin diameter. On this sheltered Southern Ocean beach, therefore,L. paivae has specialized to attack juvenile bivalves by burrowingafter them. It can, however, attack other species opportunisticallyon the sand surface when seasonally favoured juvenile bivalveprey are not present. (Received 8 January 2005; accepted 16 March 2005)     

Biological observations on the broadfin shark Lamiopsis temminckii (Carcharhiniformes: Carcharhinidae)

Biological information was collected from 214 individuals of the broadfin shark Lamiopsis temminckii measuring 418 to 1782 mm total length, L_T. Size at maturity (L₅₀) for females and males was estimated at 1430 and 1368 mm L_T, respectively, while mature and gravid females were observed from 1350 mm L_T with litter sizes 2–8 and size at birth 418–650 mm L_T. Analysis of stomach contents revealed a variety of prey, primarily crustaceans (54·0%), teleosts (42·7%) and cephalopods.     

Natural growth and reproduction in Triops granarius (Lucas) (Crustacea: Notostraca)

Field sampling during successive inundations was followed by laboratory studies on growth, egg production and hatching of Triops granarius from temporary pans in southern Africa.The species was common where mean inundation was less than one month. Sexual maturity was reached in as little as six days at a carapace length of 6.5 mm. A biomass of 2.0 g, at carapace length of 25 mm was achieved in two months. Males and females occurred in similar numbers and mating was a prerequisite for sustained fertile egg production. Eggs were in similar numbers in both pouches, while successive clutches were larger. Hatching was light-dependent. Desiccation of eggs was not necessary but a period of up to 20 days was required before undesiccated eggs would hatch. In the event of desiccation, no minimum period thereof was necessary and hatching occurred within as little as a day of rehydration. Hatching success seldom exceeded 50 percent.As a candidate for aquaculture, the species has failings such as low hatching rate and cannibalism, but it grows rapidly and produces eggs over an extended period.     

Larval and osteological development of the mote sculpin (Normanichthys crockeri) (Pisces:Normanichthyidae) from the Independencia Bight, Pisco, Peru

Ontogeny of Normanichthys crockeri is described and illustratedbased on 66 specimens (1.9–20.5 mm; including recentlyhatched larvae through to the transformation stage) collectedin Bahia Independencia, Pisco, Peru. Larvae hatch at approximately1.8 mm, undergo notochord flexion at ca. 6.2–9.0 mm, andtransform to juveniles at ca. 20.0 mm. Larvae were identifiedby the series method, using a combination of meristic and developmentalcharacters that permitted definitive identification. Diagnosticfeatures of the larvae include early development of large, lightlypigmented pectoral fins; early dorsal midline pigment on thetrunk and tail which decreases gradually to none by the beginningof the flexion stage and does not reappear until late postflexionstage; and pigment ventrally, on the midlines of the abdominaland postanal regions, on the preanal until late postflexionstage, at the angular, on the caudal region, and usually atthe cleithrum. Larvae are moderately slender with preanal lengthroughly half of body length (ca. 40–53% body length).They have I,5 pelvic-fin rays, 7+6 principal caudal-fin raysand 36–37 myomeres (11–13+24–26, usually 13+24).The cleithra and bones of the jaws and opercular series areamong the first to begin ossifying. The anterior vertebrae beginto ossify at ca. 5.0 mm and addition is posteriorly. The pectoralfin is the first to begin ray formation, followed sequentiallyby the principal caudal-fin rays, second dorsal- and anal-finrays (forming concurrently), spiny dorsal-fin rays, and pelvic-finrays.     

Observations on the larval development of Mystus macvopterus (Bleeker): Bagridae

From June to July 1988, larvae of Mystus macropterus (Bleeker) were obtained by artificial propagation of spawners collected from the Jialing River, China. Larvae grown in water temperatures ranging from 26 to 29°C were fully developed at approximately 20 days. The newly-hatched larvae measured 6.0–7.5 mm t.l. , exceeding the dimensions of any known newly-hatched larvae of freshwater catfishes indigenous to China. Five days after hatching, when the larvae were 11.4 mm t.l. and the prolarval stage was complete, exogenous feeding commenced. Twelve days after hatching, at 18.4 mm t.l. , the yolk sac disappeared, organogenesis was almost complete and the juvenile period began. At 20 days post-hatching, at 23.0 mm t.l. , the lateral line system had formed and the juveniles resembled the adults with respect to all external features, which signalled the end of thejuvenile period. Comparison of the larval development in eight species ofeconomic freshwater catfishes shows that the most significant aspect of the larval development of M. macropterus is the sustained (6–7 days) mixed nourishment period and the early differentiation of organs, which enhances the survival rate of the larvae.     

The growth rates of the estuarine mollusc Musculista arcuatula Yamamoto and Habe (Bivalvia: Mytilidae)

The pattern of growth of the total population of Musculista arcuatula over a period of thirteen months was built up plotting length-percentage frequency histograms each month. From the shifting of the modes it was noticed that the increase in size from November to December was 2 mm, the growth during December to January 3 mm. In February the growth was nil. In March the size increasing by 6 mm and in April by 1 mm, when mortality of the largest size groups started to get completed in May. In June a conspicuous mode appeared at 9 mm, grew 1 mm in July, 2 mm in August and 3 mm in September. Growth remained stationary in October and November. The rate of increase in length was found to follow exponential law. The growth rate of this bivalve goes on increasing at a steady pace, the rate being 1.086 mm per month. The mean size of the females was found to be significantly larger than that of the males. The proportion of the males in the size group 3 mm to 10 mm was found to be significantly larger than in the entire population. But in the larger size groups there was no difference in the number of males and females and the proportion was almost 1:1. Throughout the year only one age class was recognizable in the natural population. There appears to be an excessive post reproductive mortality of adults rendering the population during most of the year of a single age class recruited through the various months of spawning. The maximum longevity was found to be at the most 18 months.     

Antennal sensilla of Magicicada cassini (fisher) (Homoptera : Cicadidae): Fine structure and electrophysiological evidence for olfaction

The antennae of Magicicada cassini (Homoptera : Cicadidae) (3–4 mm long) look similar in both sexes and consist of scape, pedicel, and a 5-segmented flagellum. The length of flagellar segment 1 varies independently in relation to head size and is slightly longer in females (0.96 mm) than in males (0.89 mm). The ventral side of flagellar segment 1 is covered with sensilla coeloconica comprising about 60 large, 10 medium-sized, and 35 small sensilla with pit diameters of 8–24, 6–10, and 2 μm, respectively. The large and the medium-sized sensilla coeloconica are multiporous single-walled sensilla with pore tubules, containing branched entangled dendrites from 3 receptor cells. The small sensilla coeloconica, situated primarily at the outer border of the sensillum field, are no-pore sensilla with inflexible sockets. They contain 2 unbranched dendrites extending to the tip of the peg, and 1 dendrite reaching to its base and wrapping around the other 2 dendrites. Small sensilla campaniformia (cap diameter 3 μm) are aligned at the outer border of the sensillum field and continue all along the flagellum. Up to 3 olfactory receptor cells were distinguished on the basis of their nerve impulse amplitudes through extracellular electrophysiological recordings from sensilla coeloconica, presumably large ones. They respond to stimulation by cyclic terpenoids with different but highly overlapping reaction spectra, and react selectively to structural variations of the molecules. No responses to CO₂, temperature or moisture were recorded.     

Scyphophyllidium uruguayense n. sp. (Eucestoda: Tetraphyllidea) in Mustelus mento (Cope, 1877) (Chondrichthyes: Carcharhiniformes: Triakidae) from La Paloma, Uruguay.

A new species of Scyphophyllidium inhabits Mustelus mento near La Paloma, Uruguay. It resembles Scyphophyllidium giganteum from the Atlantic Ocean and specimens identified as S. giganteum from California by having anapolytic strobilae 155-258 mm long, 250-300 craspedote proglottids, scoleces 1.2-1.4 mm wide, necks 34-41 mm long, immature and mature proglottids wider than long, gravid proglottids wider than long to longer than wide, genital pores averaging 28% of proglottid length from the anterior end, relatively flat ovaries with digitiform lobes reaching the lateralmost extent of the testicular field, vitellaria in 2 fields converging toward the proglottid midline, straight and short cirrus sacs, and postvaginal vas deferens. The bothridia of the new species have accessory bothridial suckers that are smaller than those of California specimens; European specimens reportedly lack accessory bothridial suckers. The new species possesses a uterine duct that joins the uterus at the level of the genital atrium and ventral osmoregulatory ducts medial rather than lateral to the dorsal ducts, an arrangement described for Californian but not European specimens. It differs from both European and Californian specimens by having longer cirri, more testes per proglottid, prominent scales covering the neck, and vaginae and uterine ducts coiled immediately preovarially. Pithophorus, Marsupiobothrium, and Scyphophyllidium may form a clade.     

蜂巢奇露尾甲幼虫龄期的划分

为了明确蜂巢奇露尾甲Aethina tumida Murray幼虫的龄期和最佳分龄指标,本研究分别对不同发育阶段幼虫的头壳宽进行测量,根据各指标的频次分布结果初步确定龄期,并运用Crosby生长法则和线性回归方法进行验证分析。结果表明：蜂巢奇露尾甲幼虫可分为4龄,1~4龄头壳宽度平均值分别为0.1842 mm、0.2942 mm、0.4613 mm、0.7280 mm;此外,本文还对蜂巢奇露尾甲幼虫的形态特征进行描述。本文为研究蜂巢奇露尾甲的发生规律、生物学特性及制定防治措施等提供参考。     

Photosynthetic phosphoenolpyruvate carboxylases: characteristics of alloenzymes from leaves of c(3) and c(1) plants

A detailed comparison of green leaf phosphoenolpyruvate carboxylases from the C(4)-species Atriplex spongiosa and the C(3)-species Atriplex hastata revealed significant physical and kinetic differences. The two alloenzymes can be separated by anion exchange chromatography but have comparable molecular weights (350,000). Maximal velocity estimates were 38.0 and 1.48 micromoles per minute per milligram of chlorophyll for the carboxylases of A. spongiosa and A. hastata, respectively. Km phosphoenolpyruvate estimates were 0.49 and 0.08 mm for the C(4)A. spongiosa and C(3)A. hastata and the Km Mg estimates were 0.33 mm for the C(4) species and 0.017 mm for the C(3) species. The activity of the phosphoenolpyruvate carboxylase of A. spongiosa is more sensitive to chloride and phosphate than the phosphoenolpyruvate carboxylase of A. hastata, but both are equally sensitive to Mg chelating substances such as ATP, ADP, and citrate if assayed at their respective Km Mg values. A survey of the phosphoenolpyruvate carboxylases from 18 C(4) and C(3) species resulted in mean maximal velocity estimates of 29.0 +/- 13.2 and 1.50 +/- 0.57 micromoles per minute per milligram of chlorophyll for the C(4) species and C(3) species, respectively. Km phosphoenolpyruvate estimates were 0.59 +/- 0.35 mm and 0.14 +/- 0.07 mm for the C(4) and C(3), and Km Mg estimates were 0.50 +/- 0.30 and 0.097 +/- 0.057 mm for C(4) and C(3). All differences between means were significant at the 0.01 confidence level, supporting our hypothesis that the phosphoenolpyruvate carboxylase alloenzymes of C(4) and C(3) plants are functionally different and are associated with different photosynthetic roles. Both function in the photosynthetic production of C(4) acids, the phosphoenolpyruvate carboxylase of C(4) species largely producing malate or aspartate (or both) as a photosynthetic intermediate and the phosphoenolpyruvate carboxylase of C(3) species producing malate or aspartate (or both) as a photosynthetic product.