Causes and consequences of arm damage in the sea star Leptasterias hexactis

2000 ◽  
Vol 78 (4) ◽  
pp. 596-605 ◽  
Author(s):  
Brian L Bingham ◽  
Jennifer Burr ◽  
Herb Wounded Head
Keyword(s):  
Egg Production ◽  
Reproductive Output ◽  
Puget Sound ◽  
Adaptive Significance ◽  
Reproductive Season ◽  
Rocky Intertidal ◽  
Sea Star ◽  
Physical Disturbance ◽  
Study Sites

Leptasterias hexactis, a sea star common in rocky intertidal areas of Puget Sound, Washington, often has damaged or missing arms. We measured the frequency of arm damage in 5 populations and examined the causes and costs of the damage. Between 30 and 46% of L. hexactis found at the study sites were missing arms or parts of arms. Some of the damage, particularly when only parts of arms were missing, may result from physical disturbance (e.g., crushing). Most arm damage, however, appears to result from predation by the crab Cancer oregonensis. The ability to lose, or autotomize, arms has adaptive significance if it saves a sea star from death. However, it also carries costs. The greatest cost was a decrease in reproduction. Leptasterias hexactis missing arms showed a 44-69% drop in egg production 7 months after arm loss. The effect was still evident during the next reproductive season (19 months after arm loss). We estimate that natural levels of arm damage could decrease the reproductive output of a population of L. hexactis by 7-10%.

scholarly journals Reproductive Biology of Ovigerous Female Emerita emeritus (Crustacea, Decapoda) in Bengkulu Coastal Waters, Indonesia: Egg Production and Reproductive Output

2016 ◽  
Vol 74 (3) ◽  
pp. 103-109 ◽  
Author(s):  
Ouratul Edritanti ◽  
Achmad Farajallah ◽  
Yusli Wardiatno
Keyword(s):  
Embryonic Development ◽  
Surface Temperature ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Egg Production ◽  
Reproductive Output ◽  
Ovigerous Female ◽  
Abundant Species ◽  
Sea Surface ◽  
Egg Volume

Abstract Emerita emeritus is an abundant species in Bengkulu coastal waters, but the knowledge of its reproductive biology is poor. The present study was conducted to elucidate the reproductive aspects of ovigerous female E. emeritus, including fecundity, egg volume and reproductive output. This study was conducted between January 2015 and January 2016 in Bengkulu coastal waters, Indonesia. Samples were collected manually using shovels and hands. The results showed that ovigerous females occurred every month. Fecundity increased significantly in ovigerous females proportional to the size. No correlation was shown between sea surface temperature and egg production. Fecundity and reproductive output decreased throughout the embryonic development.

scholarly journals The reproductive performance of the Red-Algae shrimp Leander paulensis (Ortmann, 1897) (Decapoda, Palaemonidae) and the effect of post-spawning female weight gain on weight-dependent parameters

2015 ◽  
Vol 63 (3) ◽  
pp. 207-216 ◽  
Author(s):  
Uwe Zimmermann ◽  
Fabrício Lopes Carvalho ◽  
Fernando L. Mantelatto
Keyword(s):  
Weight Gain ◽  
Egg Production ◽  
Reproductive Output ◽  
Coastal Region ◽  
Reproductive Traits ◽  
Development Stage ◽  
Female Size ◽  
Egg Volume ◽  
Average Fecundity ◽  
Female Weight

AbstractDecapod species have evolved with a variety of reproductive strategies. In this study reproductive features of the palaemonid shrimp Leander paulensiswere investigated. Individuals were collected in the coastal region of Ubatuba, São Paulo, Brazil. In all, 46 ovigerous females were examined in terms of the following reproductive traits: fecundity, reproductive output, brood loss and egg volume. Leander paulensis produces a large number of small eggs with an average fecundity of 635 ± 246 eggs. Egg volume increased significantly from early (0.034 ± 0.008 mm3) to late development stage (0.05 ± 0.012 mm3). The reproductive output did not correlate with female size. The weight of females bearing stage 2 eggs was significantly higher than that of females carrying stage 1 eggs. We assume that the reason for this weight gain is the recovery of female reserves that have been depleted for egg production. Moreover, we emphasize that this weight gain must be considered when evaluating weight-dependent variables such as reproductive output or brood loss in relation to female weight. Otherwise, an overestimation of these variables might lead to inaccurate results.

Fecundity dynamics of female spiny lobster (Panulirus argus) in a south Florida fishery and Dry Tortugas National Park lobster sanctuary

2001 ◽  
Vol 52 (8) ◽  
pp. 1559 ◽  
Author(s):  
Rodney D. Bertelsen ◽  
Thomas R. Matthews
Keyword(s):  
National Park ◽  
Egg Production ◽  
Size Structure ◽  
Spiny Lobster ◽  
South Florida ◽  
Reproductive Season ◽  
Panulirus Argus ◽  
Chronological Age ◽  
Dry Tortugas ◽  
Spiny Lobsters

Using diver surveys, we compared the size structure, fecundity, and reproductive season of spiny lobsters (Panulirus argus) in the Dry Tortugas National Park lobster sanctuary with those of spiny lobsters in the south Florida fishery. The number of lobsters of both sexes larger than the legal size limit declined sharply in the fishery but not in the sanctuary. Clutch sizes were larger in the Dry Tortugas sanctuary, averaging 0.8 million, than in the fishery, averaging 0.3 million. The reproductive season was shorter and more intense in the sanctuary than in the fishery. In addition, lobsters in the sanctuary begin producing eggs at a larger size and produce more eggs per gram of body mass than lobsters in the fishery. Peak egg production occurs earlier in larger lobsters than in small ones. Establishing a fundamental reason for the differences between lobster reproduction in the sanctuary and that in the fishery is not possible until the chronological age of lobsters can be determined, but one hypothesis consistent with these differences is that, if lobsters reproduce at a certain chronological age, then sublethal fishery practices may account for slower growth for some lobsters resulting in some smaller but older reproductively active lobsters.

The impact of stem galls induced by Hemadas nubilipennis Ashmead on shoot characteristics of lowbush blueberry

2003 ◽  
Vol 83 (2) ◽  
pp. 401-408
Author(s):  
D. I. Hayman ◽  
K. E. MacKenzie ◽  
E. G. Reekie
Keyword(s):  
Nova Scotia ◽  
Good Reason ◽  
Economic Loss ◽  
Reproductive Season ◽  
Vaccinium Angustifolium ◽  
Lowbush Blueberry ◽  
Study Sites ◽  
Vegetative And Reproductive Growth ◽  
The Impact ◽  
Significant Economic Loss

The effect of galls induced by Hemadas nubilipennis Ashmead (Hymenoptera: Pteromalidae) on the morphology and reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) was studied over two seasons in three Nova Scotia blueberry fields. Comparisons of galled and non-galled shoot characteristics, and position on shoots of galls formed in the years of vegetative and reproductive growth were made. In June 1999, 30 newly galled vegetative shoots were arbitrarily selected, tagged and measured along with similar sized non-galled shoots on the galled clone and a neighbouring non-galled clone. Shoot characteristics were measured in the reproductive season during bloom and after harvest. At two sites, the dry weights of leaves and stems on galled shoots measured in the reproductive season were significantly less than non-galled shoots, but at a third site there was no difference in stem allocation. Galls reduced berry production on shoots at two sites. Proportions of terminally positioned galls differed significantly among study sites in the reproductive season. Shoots with terminal galls were significantly shorter, lighter and allocated less weight to leaves and stems than shoots with basally positioned galls. If the reports of increasing gall populations in Nova Scotia during the 1990s are correct, there may be good reason to believe that there will be significant economic loss of blueberries in the future. Key words: Gall, blueberry (lowbush), Hemadas nubilipennis, Vaccinium angustifolium

Biomass allocation to vegetative and reproductive organs in Lotus glaber and L. corniculatus (Fabaceae)

2002 ◽  
Vol 50 (1) ◽  
pp. 75 ◽  
Author(s):  
O. R. Vignolio ◽  
O. N. Fernández ◽  
N. O. Maceira
Keyword(s):  
Biomass Allocation ◽  
Reproductive Output ◽  
Specific Weight ◽  
Growth Conditions ◽  
Reproductive Organs ◽  
Reproductive Season ◽  
Lower Weight ◽  
Reproductive Biomass ◽  
Pod Length ◽  
Lotus Glaber

Comparative studies on reproductive and vegetative attributes between Lotus glaber Mill. and L. corniculatus L. showed that under identical growth conditions seed and pod production were higher in L. glaber than in L. corniculatus. The objective of this work was to determine whether differences in reproductive output between L. glaber and L. corniculatus are related to differences in biomass allocation and whether they can be related to the habitats of each species. We compared, in two studies, the allocation of vegetative and reproductive biomass of both species' growth in pots outdoors. The shoot to root ratio was higher in L. glaber than in L. corniculatus. Both species allocated the same biomass to stems but L. corniculatus produced fewer reproductive stems of higher specific weight. The number of pods per umbel and seeds per pod did not differ between species, but the total number of umbels, pods and seeds per plant were higher in L. glaber than in L. corniculatus. Weight per pod was higher in L. corniculatus than in L. glaber. The reproductive biomass in L. glaber was distributed in a higher number of pods and seeds that were of lower weight than in L. corniculatus. In both species, pod length and seed number per pod showed a decreasing trend during the reproductive season and both attributes were positively correlated. Some of the differences reported in reproductive and vegetative attributes are consistent with the conditions of habitat where each species grows. The results are discussed in relation to the agronomic values of these species and the factors determining their persistence and distribution in the grassland.

Determining the appropriate time and hormone administration for induced spawning and egg production of the shoemaker spinefoot rabbitfish, Siganus sutor (Valenciennes, 1835) during the reproductive season

Aquaculture ◽  
2019 ◽  
Vol 510 ◽  
pp. 318-322
Author(s):  
Hojjatollah Fourooghifard ◽  
Kiuomars Roohani Ghadikolaee ◽  
Samuel Allen ◽  
Maryam Moezzi ◽  
Reza Dehghani ◽  
...  
Keyword(s):  
Egg Production ◽  
Reproductive Season ◽  
Induced Spawning ◽  
Hormone Administration

Love for sale and its fitness benefits: nuptial gifts in the scorpionfly Panorpa vulgaris represent paternal investment

Behaviour ◽  
2006 ◽  
Vol 143 (7) ◽  
pp. 825-837 ◽  
Author(s):  
Sierk Engels ◽  
Klaus Peter Sauer
Keyword(s):  
Egg Production ◽  
Reproductive Output ◽  
Mating Effort ◽  
Nuptial Gift ◽  
Paternal Investment ◽  
Nuptial Gifts ◽  
Female Fecundity ◽  
Nuptial Feeding ◽  
Common Strategy ◽  
Fitness Benefits

AbstractNuptial feeding is a very common strategy shown by males of various insect taxa in order to obtain copulations. In the majority of cases these gifts presented during or after courtship and/or copulation can be considered as mating effort. In this study we present data which indicate that nuptial feeding in Panorpa vulgaris (Mecoptera: Panorpidae) represents paternal investment. During copulations males produce salivary secretions which are consumed by the females. The more salivary masses a male produces the longer the copulation will last. Since sperm are transferred continuously during copulation and fertilization of eggs follows the fair raffle principle, females allocate paternity in accordance to copulation duration and therefore to the amount of nuptial gifts they receive from a certain male. In the present study we are able to show that the number of salivary masses consumed significantly affects the number of eggs a female produces. Thus, in P. vulgaris the nuptial gift increases the reproductive output of females and hence must not only be considered as mating effort but also as paternal investment. The mechanism by which salivary masses increase female fecundity is yet unknown. We hypothesize that the secretions may not only transfer nutrients but may possibly operate as carriers for an allohormone that manipulates the females' physiology in terms of increasing egg production.

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