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Age data are crucial for understanding and managing target species in commercial and recreational fisheries. Octopus catches are increasing worldwide, yet ageing methods are still in their infancy. Octopus age is estimated by counting growth increments in stylets and beaks. These increments have been validated as daily in some species or assumed to be daily in other species. Here, we conducted an age validation study on both the stylets and beaks of a commercial octopus species (Octopus berrima). Subsequently, we compared and assessed the readability of growth increments in beaks and stylets of wild-caught O. berrima. We found that increment periodicity was nondaily for both structures, with increment periodicity also varying between structures (0.75 increments per day for stylets and 0.53 increments per day for beak). This study highlights the importance of validating increment periodicity for different octopus species and for both stylets and beaks to obtain accurate age and growth data. Without accurate age data, a species may be incorrectly managed with the potential for negative effects on the sustainability of wild populations. [ABSTRACT FROM AUTHOR]

Baleen whales are one of the few vertebrate taxa for which there are no confirmed estimates of longevity or methods of age determination. Lamina counts in the waxy earplug are assumed to represent age, but ageing accuracy is completely unknown. In this study, bomb radiocarbon assays of the earplug growth sequence in three adult fin whales (Balaenoptera physalus) were used to prepare the most complete within-individual bomb radiocarbon chronologies yet reported for any vertebrate. The whale radiocarbon chronologies matched those of known-age carbonate reference chronologies very well, indicating that the earplug laminae were both metabolically stable and formed throughout the life of the whale. Earplug lamina counts accurately represented absolute ages of 65-85 yr to within 6% of the correct age. Detection of a significant declining trend in δ13Cwithyear of lamina formation within individual whales was consistent with that of the Suess effect, again underlining the metabolic stability of the earplug laminae. Given our results, recent applications of earplug laminae for reconstructing diet and life history events appear to be firmly based, with the potential for further elemental and isotopic applications analogous to those of the otolith. [ABSTRACT FROM AUTHOR]

Baleen whales are one of the few vertebrate taxa for which there are no confirmed estimates of longevity or methods of age determination. Lamina counts in the waxy earplug are assumed to represent age, but ageing accuracy is completely unknown. In this study, bomb radiocarbon assays of the earplug growth sequence in three adult fin whales (Balaenoptera physalus) were used to prepare the most complete within-individual bomb radiocarbon chronologies yet reported for any vertebrate. The whale radiocarbon chronologies matched those of known-age carbonate reference chronologies very well, indicating that the earplug laminae were both metabolically stable and formed throughout the life of the whale. Earplug lamina counts accurately represented absolute ages of 65-85 yr to within 6% of the correct age. Detection of a significant declining trend in δ13C with year of lamina formation within individual whales was consistent with that of the Suess effect, again underlining the metabolic stability of the earplug laminae. Given our results, recent applications of earplug laminae for reconstructing diet and life history events appear to be firmly based, with the potential for further elemental and isotopic applications analogous to those of the otolith.

Abstract Relationships between growth increments of internal shell and age was studied in three neritic decapod cephalopods cultured in laboratory through their entire life cycles. The studied cephalopods were the nektic Sepioteuthis lessoniana d’Orbigny, 1826, Sepia pharaonis Ehrenberg, 1831 and Sepiella inermis Van Hasselt, 1835. Most of the relationship models are in cubic parabolic, except when numbers of increments were estimated from age in S. pharaonis. Differences of numbers of increments from the real age were higher in the pelagic S. lessoniana when compared to the benthic sepiids. The differences were higher in juvenile stages ( 60 days) in the three species. The increment rate is close to the “one day one increment” assumption. The differences of numbers of increments from the ages and the rate of increment apposition revealed the transition point of the life cycle from 60 days of age, corresponding to the sexual maturity or adult stages. Numbers of increments with higher accuracy are reevaluated to be reliable for age determination at least for the neritic species in the tropical zone, where environmental conditions are more stable, regarding the life styles and stages in life cycles of each species.

Beaks are one of the most important sclerochronological structures used to study the age and growth of cephalopods, in particular Octopus vulgaris Cuvier, 1797. The present study provides results of ageing of 128 O. vulgaris (56–239 mm dorsal mantle length, DML; 121–5974 g total weight, TW) collected in the southern Moroccan Mediterranean coasts between Fnideq and Jebha. The number of increments corresponding to the age (days since hatching) varied from 137–368 in females and from 129–382 in males. There was a significant correlation between beak and somatic growth. The correlation coefficients of the growth curves DML-Age and TW-Age were similar for both power and exponential models: DML = 0.185Age1.188 (R 2 = 0.547), DML = 35.933e0.005Age (R 2 = 0.546), TW = 0.00002Age3.260 (R 2 = 0.532), TW = 29.56e0.014Age (R 2 = 0.541). The average width of the increments was similar between females and males. It varied significantly with season and stage of sexual maturity. Comparison of the growth curve with those estimated by other authors showed that Moroccan Mediterranean O. vulgaris grew faster than that of Sardinia (Italy) and slower than that of the Mauritanian coast. [ABSTRACT FROM AUTHOR]

Treated wastewater can partly meet the requirements of water for irrigating tree crops in dry areas to better utilize, produce biomass and reduce land degradation. Seedlings of Acacia nilotica, Azadirachta indica, Eucalyptus camaldulensis, Prosopis cineraria, P. juliflora, Tamarix aphylla, Salvadora persica, S. oleoides and Tecomella undulata were planted and irrigated with bore-well (BW) and treated wastewater (WW) at ½ET (Evaporation-transpiration) and ¾ET. Plants irrigated at BW1/2 attained less height and collar diameter, and showed low growth increments and dry biomass. These variables increased by 1.2-2.0-fold at WW3/4 irrigation. Plants produced 1.4-fold higher biomass with WW over BW, whereas it was 1.5-fold higher at ¾ET over ½ET. Responses of species to BW/WW irrigation differed in biomass allocation to roots and other parts as a mechanism to uptake water and nutrients. Conclusively, A. nilotica, A. indica, P. juliflora and T. aphylla had stronger preference to increased irrigation level, whereas E. camaldulensis, S. persica, S. oleoides and T. undulata had preferred nutrients added through treated wastewater. A. nilotica, E. camaldulensis, P. juliflora and A. indica were best species in growth and biomass production and wastewater utilization. These can be replicated in urban afforestation to enhance bio-product and reduce degradation in environmental quality. Wastewater (WW) is an alternative source of water in dryland afforestation. Wastewater was characterized and utilized in growing tree plantation in Indian arid zone. Plant growth and biomass increased with treated wastewater irrigation. Responses of different species to wastewater differed depending on their phytoremediation ability by nutrient uptake and biomass distribution. Tree species differed in their preferences to increased quantity of irrigation water and nutrients added through wastewater application. [ABSTRACT FROM AUTHOR]

Paleoclimate and paleoenvironmental reconstructions from increment-yielding archives strongly depend on precise age models. Like bivalves, corals, trees, and speleothems, the coralline alga Clathromorphum compactum produces annual growth increments and shows considerable promise as an environmental archive for arctic and subarctic regions. Though their growth increment widths correlate with temperature and sea ice cover in high Arctic regions, existing timeseries have not been crossdated. In fact, previous studies have shown a lack of inter-sample correlation in non-crossdated timeseries suggesting possible age model dating errors. Here, we use dendrochronology crossdating techniques and COFECHA software to ensure and validate synchrony between C. compactum timeseries (

Relationships between growth increments of internal shell and age was studied in three neritic decapod cephalopods cultured in laboratory through their entire life cycles. The studied cephalopods were the nektic Sepioteuthis lessoniana d’Orbigny, 1826, Sepia pharaonis Ehrenberg, 1831 and Sepiella inermis Van Hasselt, 1835. Most of the relationship models are in cubic parabolic, except when numbers of increments were estimated from age in S. pharaonis. Differences of numbers of increments from the real age were higher in the pelagic S. lessoniana when compared to the benthic sepiids. The differences were higher in juvenile stages (< 60 days after hatching) than adult stages (> 60 days) in the three species. The increment rate is close to the “one day one increment” assumption. The differences of numbers of increments from the ages and the rate of increment apposition revealed the transition point of the life cycle from 60 days of age, corresponding to the sexual maturity or adult stages. Numbers of increments with higher accuracy are reevaluated to be reliable for age determination at least for the neritic species in the tropical zone, where environmental conditions are more stable, regarding the life styles and stages in life cycles of each species. [ABSTRACT FROM AUTHOR]