scholarly journals Notes on the growth and biology of the prawn Pandalus bonnieri Caullery

1952 ◽  
Vol 31 (2) ◽  
pp. 259-267 ◽  
Author(s):  
R. B. Pike
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Carapace Length ◽  
Size Group ◽  
Dioecious Species ◽  
Male And Female ◽  
Males And Females ◽  
Sexually Mature

Pandalus bonnieri is a dioecious species and no protandrous hermaphrodites have been seen.The breeding season and incubation period for P. bonnieri are described.The number of eggs laid increases with the size of the female. At 16 mm. carapace length the number of eggs is c. 1000 and at 24 mm. carapace length the number of eggs is c. 4000. The number for a single mm. size group varies roughly by ±10%.Both male and female P. bonnieri become sexually mature at about 18 months, and in the Clyde seldom live beyond 3 years of age.The colour of the eggs in P. bonnieri is sage green, in P. borealis blue green, in P. montagui light emerald green and in P. propinquus fawn.Juvenile P. bonnieri can be separated into males and females by the shape of the pleopods within 4–6 months of hatching.

scholarly journals Notes on the growth and biology of the prawn Spirontocaris lilljeborgii (Danielssen)

1954 ◽  
Vol 33 (3) ◽  
pp. 739-747 ◽  
Author(s):  
R. B. Pike
Keyword(s):  
Incubation Period ◽  
Small Proportion ◽  
Egg Laying ◽  
First Year ◽  
Dioecious Species ◽  
Eye Pigmentation ◽  
Males And Females ◽  
Second Year ◽  
Sexually Mature

SummarySpirontocaris lilljeborgii is a dioecious species and no protandrous hermaphrodites have been seen.The majority of males become sexually mature in the first year (7–9 months). Some of these may die after fertilizing the females and the majority die after fertilizing the females for a second year (18 months old).Only a small proportion of the females breed in their first year, all breed during their second year and a few appear to live for a third year.A first-year female lays from 130 to 160 eggs, and the usual output of a second-year female is from 450 to 650 eggs.Egg laying begins at the end of November and hatching is complete by the end of March.The total incubation period is about 90 days. Eye pigmentation first appears at about half the incubation period (47 days).Juveniles can be distinguished as males and females by the shape of their pleopods within 4–6 months of hatching.

scholarly journals Breeding Biology of Gray-Crowned Tyrannulet in the Monte Desert, Argentina

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Eduardo T. Mezquida ◽  
Luis Marone
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Nesting Success ◽  
Nest Failure ◽  
East Central ◽  
Male And Female ◽  
Monte Desert ◽  
Present Information ◽  
Nestling Period ◽  
Wet Tropics

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

scholarly journals Redescriptions of two species of Sepia (Cephalopoda: Sepiidae) from South African waters: Sepia robsoni (Massy, 1927) and S. faurei Roeleveld, 1972

2020 ◽  
Vol 28 (4) ◽  
pp. 253-285
Author(s):  
Marek R. Lipiński
Keyword(s):  
South African ◽  
Distinct Group ◽  
Mantle Length ◽  
Aquatic Biodiversity ◽  
Male And Female ◽  
Long Time ◽  
Smooth Skin ◽  
Males And Females ◽  
Bottom Depth ◽  
Sexually Mature

Two species of cuttlefish: Sepia robsoni (Massy) and Sepia faurei Roeleveld, are redescribed based on sexually mature males and females of both species. They were previously known only from their holotypes: male and female, respectively. They belong to a distinct group of small-sized sepiids, all near-endemics of southern African waters. The knowledge of the systematics and biology of this group is still limited despite the long time since the first description (1875). This is because, inter alia, of their small size: not larger than 4 cm mantle length at maturity. Twenty-one individuals of S. robsoni described here were scattered from Port Nolloth area to the Tsitsikamma coast (bottom depth <37–449 m). Eight known individuals of S. faurei came from the eastern Agulhas Bank (bottom depth 116–184 m). S. robsoni can be identified by extremely thinly calcified cuttlebone (transparent); smooth skin of dorsal mantle and head; tips of first pair of arms thick, finger-like, devoid of suckers. S. faurei can be distinguished by the following combination of characters: thick, heavily calcified cuttlebone but with flat and fused inner cone; skin of dorsal mantle and head very densely covered by characteristic warts; thin, whip-like tips of first pair of arms devoid of suckers. All described specimens of both species are deposited in the South African Institute of Aquatic Biodiversity (SAIAB) and in Iziko, South African Museum (SAMC).

Catchability of the southern rock lobster Jasus edwardsii. I. Effects of sex, season and catch history

2002 ◽  
Vol 53 (8) ◽  
pp. 1143 ◽  
Author(s):  
P. E. Ziegler ◽  
S. D. Frusher ◽  
C. R. Johnson ◽  
C. Gardner
Keyword(s):  
Carapace Length ◽  
Early Summer ◽  
Rock Lobster ◽  
Marked Contrast ◽  
Density Estimates ◽  
Male And Female ◽  
Jasus Edwardsii ◽  
Males And Females ◽  
Catch Rates ◽  
Trap Catches

Seasonal variation in catchability of the southern rock lobster Jasus edwardsii, was estimated in a scientific reserve in south-east Tasmania by comparing estimates of lobster density based on direct visual observations underwater with concomitant estimates from trapping surveys. Underwater density estimates of undersized and legal-sized male and female lobsters >80 mm carapace length, did not change significantly over the 14-month study period, with the exception of undersized males (≤110 mm carapace length). Sex ratios remained constant at approximately 1 : 1. In marked contrast, catch rates of males and females and the sex ratio of trapped lobsters varied strongly with season, implying that catchability varies seasonally and with sex. Catchability of males and females was highest in early summer and lowest in winter. Impact of capture on subsequent catchability appeared to be weak, since the ratios of tagged animals in the population observed underwater generally reflected recapture rates of tagged animals in trap catches. Recapture rates increased with size and were higher for medium-sized and large males than for similar-sized females. However, for each particular sex-size group, recapture rates remained relatively constant throughout the study period.

Biology of the cucurbit fruit fly, Bactrocera cucurbitae (Coq) on host bottle gourd, Lagenaria siceraria

2020 ◽  
Vol 25 (2) ◽  
pp. 2098-2106
Author(s):  
T. Akter ◽  
M. M. H. Sohel
Keyword(s):  
Incubation Period ◽  
Fruit Fly ◽  
Bottle Gourd ◽  
Adult Longevity ◽  
Lagenaria Siceraria ◽  
Bactrocera Cucurbitae ◽  
Male And Female ◽  
Larval Instars ◽  
Males And Females ◽  
The Mean

We investigated the biology of the cucurbit fruit fly, Bactrocera cucurbitae (coq) on bottle gourd, Lagenaria siceraria, using variety ‘BARI-Lau 1’. The mean incubation period, larval (1st, 2nd and 3rd instars), pre-pupal, pupal and total developmental periods of B. cucurbitae were 1.69±0.28, (1.72±0.33, 1.41±0.31, 2.31±0.51), 0.74±0.28, 9.2±0.78 and 36±1.69 days, respectively. The mean adult longevity, with food and without food was 14.1±1.28 and 5.0±0.81 days, respectively. The lengths of all three larval instars were 1.1± 0.9, 3.03 ± 0.95 and 6.42 ± 0.90 mm, and the widths were 0.22 ±0.11, 1.12 ± 0.01 and 2.13 ± 0.20 mm, respectively. The length and width of the pre-pupa and the pupa were 5.86 ±0.48, 5.68± 0.26 mm and 1.94 ± 0.23, 2.39±0.20 mm respectively. The length of male and female were 6.61±0.59 and 8.28±0.52 mm. The widths of males and females with wingspan were 10.97 ± 0.43 and 13.02±1.28 mm respectively. The incidence of B. cucurbitae as maggot population in bottle gourd was higher in January during the study period from December 2018 to March 2019.

Population structure, growth rates and spatial distribution of two dioecious tree species in a wet forest in Puerto Rico

2010 ◽  
Vol 26 (4) ◽  
pp. 433-443 ◽  
Author(s):  
Jimena Forero-Montaña ◽  
Jess K. Zimmerman ◽  
Jill Thompson
Keyword(s):  
Growth Rate ◽  
Puerto Rico ◽  
Life History ◽  
Growth Rates ◽  
Cost Of Reproduction ◽  
Sexual Differences ◽  
Reproductive Costs ◽  
Dioecious Species ◽  
Male And Female ◽  
Males And Females

Abstract:Dioecious plants often exhibit male-biased sex ratios and sexual differences in life history traits such as plant size, growth rate and frequency of flowering, which arise from the different costs of reproduction for male and female plants. In tropical dioecious species sexual differences in reproductive costs have been demonstrated for several subcanopy species, but few canopy dioecious trees have been studied. We recorded the sexual expression of c. 2600 trees of Cecropia schreberiana and Dacryodes excelsa, two canopy dioecious species, during several censuses over 2 y in a 16-ha plot located in ‘subtropical wet forest’ in the Luquillo Mountains, Puerto Rico. There were similar numbers of male and female trees of C. schreberiana but D. excelsa had a female-biased population. Cecropia schreberiana showed no differences in male and female diameter distributions or growth rates, suggesting that reproductive maturation and longevity are similar for both sexes. This lack of differences in size and growth rate in C. schreberiana may result from mechanisms to compensate for the higher cost of reproduction in females, no resource limitation related to its pioneer life-history, or similar male and female reproductive costs. In contrast, D. excelsa males were larger than females, probably because males grow slightly faster than females. This sexual difference in D. excelsa may reflect a higher cost of reproduction in females than in males. Spatial segregation of males and females into different habitats is not common in tropical forest and neither C. schreberiana nor D. excelsa males and females exhibited significant spatial segregation. The contrasting results for these two canopy species reflect their different life history strategies in this hurricane-affected forest.

Reproduction in Antechinomys laniger ('spenceri' Form) ( Marsupialia : Dasyuridae): Field and Laboratory

1984 ◽  
Vol 11 (3) ◽  
pp. 481 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Breeding Season ◽  
Oestrous Cycle ◽  
Average Rainfall ◽  
Proximate Factor ◽  
Breeding Condition ◽  
Males And Females ◽  
Sexually Mature ◽  
Length Of Gestation

Antechinomys laniger is polyoestrous, and animals from Sandringham Station in south-western Queensland are in breeding condition from midwinter to midsummer. Laboratory observations suggest that photoperiod may be the proximate factor controlling the timing of the breeding season. Females enter oestrus up to six times during the season, and as the season progresses the length of the oestrous cycle decreases. The estimated length of gestation is 12 days or less. Females may rear up to six young. The young are weaned when about 3 months old and become sexually mature at 11.5 months. Both males and females are potentially capable of breeding in more than one season. Higher than average rainfall may have led to a decline in the numbers of A. laniger on Sandringham Station.

Seasonal endocrine changes in male and female Arctic charr (Salvelinus alpinus). I. Plasma levels of three androgens, 17α-hydroxy-20β-dihydroprogesterone, and 17β-estradiol

1992 ◽  
Vol 70 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Ian Mayer ◽  
Monika Schmitz ◽  
Bertil Borg ◽  
Rüdiger Schulz
Keyword(s):  
Breeding Season ◽  
Adult Male ◽  
Annual Cycle ◽  
Plasma Levels ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Male And Female ◽  
17Β Estradiol ◽  
Males And Females

Plasma levels of the androgens testosterone (T), 11-ketotestosterone (OT), and 11-ketoandrostenedione (OA), the progestin 17α-hydroxy-20β-dihydroprogesterone (17,20-P), and 17β-estradiol (E2) were measured by radioimmunoassay over the annual cycle in both adult male and female Arctic charr (Salvelinus alpinus). In both males and females plasma T, OT, and OA all reached their highest levels during the early breeding season in September. The dominant androgen in maturing males was OT, which reached levels of ca. 90 ng/mL. Plasma levels of OT and OA, but not T, were considerably higher in males than in females; 17,20-P peaked later than the androgens, in November in males (14 ng/mL) and October in females (0.8 ng/mL). E2 was always low or nondetectable in males. In maturing females E2 peaked in August (3.5 ng/mL) before falling concomitantly with rising T levels. From January to April plasma levels of all measured steroids were low in both males and females.

Biometric relationships of the spotted lobster, Panulirus echinatus, from Tamandaré coastal reefs, Pernambuco State, Brazil

2009 ◽  
Vol 89 (8) ◽  
pp. 1601-1606 ◽  
Author(s):  
Aline do Vale Barreto ◽  
Maria de Lourdes Zani-Teixeira ◽  
Carlos Tassito Correa Ivo ◽  
Mario Katsuragawa
Keyword(s):  
Carapace Length ◽  
Total Weight ◽  
Body Measurements ◽  
Allometric Growth ◽  
Male And Female ◽  
Total Length ◽  
Males And Females

Biometric relationships were recorded for 2431 male and female Panulirus echinatus sampled at Tamandaré coastal reefs, Pernambuco, Brazil. The following body measurements were taken: carapace length and width, abdomen length and width, total length, third and fifth pereiopod length, cephalothorax–abdomen and total weight. Twelve relationships were studied to compare the biometric characteristics of males and females. Eleven of them showed difference between the sexes. Comparing sexes with the same carapace length, males have a heavier cephalothorax and longer third and fifth pereiopods than females, whereas females are longer, wider, and have a heavier abdomen than males. For genders with the same total length, males are heavier and have a longer carapace than females, while females have a larger abdomen. For genders with the same abdomen length, males have a heavier abdomen than females. The relationships TWg/TL and AWg/AL showed positive allometric growth for the males. All other relationships involving weight, presented negative allometric growth for both sexes.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

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