Effects of experimental manipulations on the life history pattern of Lymnaea stagnalis appressa say (pulmonata: lymnaeidae)

Hydrobiologia ◽  
1979 ◽  
Vol 65 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Kenneth M. Brown
Keyword(s):  
Life History ◽  
Lymnaea Stagnalis ◽  
Life History Pattern

scholarly journals Brain ontogeny and life history in Pleistocene hominins

2015 ◽  
Vol 370 (1663) ◽  
pp. 20140062 ◽  
Author(s):  
Jean-Jacques Hublin ◽  
Simon Neubauer ◽  
Philipp Gunz
Keyword(s):  
Life History ◽  
Cognitive Complexity ◽  
Extended Period ◽  
Brain Structures ◽  
Human Model ◽  
Evolutionary Pathway ◽  
Life History Pattern ◽  
Delayed Maturation ◽  
High Level ◽  
The Brain

A high level of encephalization is critical to the human adaptive niche and emerged among hominins over the course of the past 2 Myr. Evolving larger brains required important adaptive adjustments, in particular regarding energy allocation and life history. These adaptations included a relatively small brain at birth and a protracted growth of highly dependent offspring within a complex social environment. In turn, the extended period of growth and delayed maturation of the brain structures of humans contribute to their cognitive complexity. The current palaeoanthropological evidence shows that, regarding life history and brain ontogeny, the Pleistocene hominin taxa display different patterns and that one cannot simply contrast an ‘ape-model’ to a ‘human-model’. Large-brained hominins such as Upper Pleistocene Neandertals have evolved along their own evolutionary pathway and can be distinguished from modern humans in terms of growth pattern and brain development. The life-history pattern and brain ontogeny of extant humans emerged only recently in the course of human evolution.

The influence of maternal effects in larval survival on fishery harvest reference points for two life-history patterns

2014 ◽  
Vol 71 (1) ◽  
pp. 151-161 ◽  
Author(s):  
Paul D. Spencer ◽  
Sarah B.M. Kraak ◽  
Edward A. Trippel
Keyword(s):  
Life History ◽  
Pacific Ocean ◽  
Maternal Effects ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Larval Survival ◽  
Reference Points ◽  
Life History Pattern ◽  
Gadus Macrocephalus ◽  
Potential Interactions

Increased larval viability with increased spawner age (i.e., maternal effects) have been observed in Atlantic cod (Gadus morhua) and Pacific rockfish (Sebastes spp.) stocks. Analytical results from a Beverton–Holt recruitment model indicate density-independent maternal effects affected the relative stock productivity and fishing rate reference points. We simulated populations based on Pacific cod (Gadus macrocephalus) and Pacific ocean perch (Sebastes alutus) to explore how estimates of reference points Fmsy and Fcrash are affected by maternal effects and potential interactions with life-history pattern, recruitment autocorrelation, and exploitation rate. Estimates of Fmsy and Fcrash were made from populations with maternal effects using either total larvae (proportional to eggs) or viable larvae (incorporating the maternal effect). Maternal effects have the largest impact upon estimated population productivity at high fishing rates. Estimates of Fmsy and Fcrash for cod were also affected by autocorrelated recruitment variability because of their reduced longevity compared with Pacific ocean perch. These results suggest the importance of evaluating the influence of maternal effects on estimated stock productivity on a case-by-case basis, particularly for depleted stocks composed of relatively young spawners.

Capital or income breeding crabs: who are the better invaders?

Crustaceana ◽  
2014 ◽  
Vol 87 (14) ◽  
pp. 1648-1656 ◽  
Author(s):  
Yiwen Zeng ◽  
Colin McLay ◽  
Darren C. J. Yeo
Keyword(s):  
Life History ◽  
Gonadosomatic Index ◽  
Carcinus Maenas ◽  
Breeding Strategy ◽  
Life History Trait ◽  
Hepatosomatic Index ◽  
Hemigrapsus Sanguineus ◽  
Life History Pattern ◽  
Income Breeding ◽  
Capital Breeder

A recent study by Griffen et al. (2012) drew a link between invasiveness and breeding strategy (income or capital breeding), a hitherto unconsidered life-history trait, in crabs. The methods used by the authors identified Carcinus maenas (Linnaeus, 1758) as a capital breeder and Hemigrapsus sanguineus (De Haan, 1853) as an income breeder. We extend this association of breeding strategies and invasiveness to other crab species and note that crabs in general are capital breeders based on the concurrent opposing trends of gonadosomatic index and hepatosomatic index during secondary vitellogenesis (indicating an endogenous source of nutrients for reproduction). We identify possible reasons why H. sanguineus may be regarded as an exception to this brachyuran life history pattern. Given that some species could be capable of a mixed breeding strategy, we propose experimental methods for determining such strategies.

Quantitative distributional patterns and aspects of the biology of the Mysidacea (Crustacea: Peracarida) in the zooplankton of the Bay of Fundy region

1988 ◽  
Vol 66 (7) ◽  
pp. 1545-1552 ◽  
Author(s):  
Susan Corey
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Food Source ◽  
Bay Of Fundy ◽  
Adult Fish ◽  
Great Abundance ◽  
Life History Pattern ◽  
Distributional Patterns ◽  
Passamaquoddy Bay

Three mysids, Erythrops erythropthalma, Mysis stenolepis, and Neomysis americana occurred in the zooplankton of the Bay of Fundy and adjacent waters from 1973 through 1981. Erythrops erythropthalma occurred in low numbers in scattered areas, such as the mouth of Passamaquoddy Bay, Grand Manan Channel, the coast of Maine, and off St. Mary's Bay and southwest Nova Scotia. Mysis stenolepis was taken rarely and only in the shallower stations near the coast and in the inner Bay of Fundy. Neomysis americana was the most abundant mysid and the most widespread in its distribution. Populations were found at the head of the Bay of Fundy and in St. Mary's Bay. Seasonally, N. americana was least abundant in the spring, with numbers and area of distribution increasing in the summer and fall. The life history pattern of N. americana in the inner Bay of Fundy was the same as that found in other areas nearby. It rarely occurred in depths greater than 75 m and was more abundant in the zooplankton at night than during the day. Because of the great abundance of N. americana in the inner Bay of Fundy and St. Mary's Bay, it provides an excellent food source for larval and adult fish in these areas.

Comparative life histories of a low- and a high-elevation population of the common frog Rana temporaria

1996 ◽  
Vol 17 (3) ◽  
pp. 183-195 ◽  
Author(s):  
Jan Ryser
Keyword(s):  
Life History ◽  
Life Histories ◽  
Rana Temporaria ◽  
High Elevation ◽  
Swiss Alps ◽  
Life History Pattern ◽  
Frog Rana Temporaria ◽  
The Alps ◽  
Breeding Pond ◽  
The Common

AbstractCommon frogs from a breeding pond in the Swiss Alps (1930 m) were studied by skeletochronology and life history traits were compared to a previously described lowland population. Snout-vent lengths ranged from 63 to 85 mm (males) and 65 to 94 mm (females). Ages varied from 4 to 13 years with means of 6.6 (males) and 8.3 years (females). Growth of immature frogs was slow. Immature males grew faster than females, but the reverse was true for adult frogs. Egg numbers ranged from 784 to 1616 and were not correlated with snout-vent length. Egg diameters (1.83-2.19 mm) were positively correlated with snout-vent length. Frogs from the Alps differed from the lowland population in slower growth to maturation, resulting in higher ages, but similar sizes, at first reproduction. I argue that the alpine life history pattern was shaped by two environmentally determined traits, slow growth and high annual survival.

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