Atherina Hepsetus Research Articles

Marmara Denizi’nde Gümüş Balığı (Atherina hepsetus Linnaeus 1758) Avcılığında Kullanılan Uzatma Ağlarının Modifikasyonu ve Av Verimi Üzerine Etkileri

Gümüş balığı; tüketim amaçlı kullanılmanın yanında, İstanbul Boğazı, Çanakkale Boğazı ve çevrelerinde olta ile lüfer avcılığında yem olarak kullanılmaktadır. Gümüş balığı, özellikle lüfer avcılığı döneminde ticari balıkçılar tarafından sade uzatma ağları ile yoğun olarak avlanmaktadır. Bu çalışmada Güney Marmara’da bir balıkçının 2014-2019 yılları arasındaki 2 yıllık periyotlarda gümüş balığı avcılığında kullandığı sade uzatma ağlarının teknik özellikleri ve yıllara göre ağlarında gerçekleştirdiği modifikasyonlar tespit edilmiştir. 2016-2017 yılında 2014-2015 yılına göre ağ göz açıklığı, ip kalınlığı, ağ rengi, ağ yüksekliği, mantar büyüklüğü, ağ uzunluğu; 2018-2019 yılında 2016-2017 yılına göre ip kalınlığı, ağ yüksekliği, ağ uzunluğunda modifikasyonlar yapıldığı belirlenmiştir. Ağlarda gerçekleştirilen modifikasyonlar sonucunda av veriminde 2017-2018 yılında 2016-2017 yılına göre av veriminde 5,79 kat artış olduğu tespit edilmiştir. En yüksek birim av miktarları (BAVM) 2016-2017 yılında 06:00 ile 08:59 saatleri (0.041 adet/m2.operasyon-1) arasında, 2017-2018 yılında ise 09:00 ile 11:59 saatleri (0.175 adet/m2.operasyon-1) arasında tespit edilmiştir. En yüksek BAVM kuş sürüsü avcılık yöntemi (1,309 adet/m2.operasyon-1) ile en düşük BAVM ise rastgele avcılık yöntemi (0.082 adet/m2.operasyon-1) ile belirlenmiştir. 2016-2017 ve 2017-2018 yılında avlanan uzatma ağları ile avlanan gümüş balıklarının ortalama boyları sırasıyla 12,7±0.09 cm, 12,7±0.07 cm; ortalama ağırlığı ise 12,6±0.21 gr, 13,1±0.17 gr olarak hesaplanmıştır. Bu çalışmada Atherina hepsetus’un uzatma ağları ile avcılığı ilk kez tanımlanmıştır. Hedeflenen bir türün avcılığında etkin bir şekilde kullanılan uzatma ağlarının ilk kez tanımlanması ile yıllara göre av veriminin, avlama yöntemlerinin ve av saatlerinin, av verimine etkilerinin tespit edilmesi balıkçılık yönetimi ve sürdürülebilir balıkçılık açısından önemlidir.

First data on the diet of Razorbill Alca torda wintering in the Mediterranean Sea: insights from social media

Understanding a species’ diet is of paramount importance to ecology as it provides vital insights into interactions between organisms and their environment. In this study, we report the first data on the diet of wintering Razorbills (Alca torda) in the Mediterranean Sea. Taking advantage of the irruption event that occurred in the Mediterranean in winter 2022/2023, a data mining search campaign was carried out on social media to collect photographs and videos documenting Razorbills feeding at sea. Additional information was gathered by analysing the stomach contents of dead individuals salvaged from the coastline of central Italy. Overall, we obtained records from 32 pictures and 7 videos as well as 7 dead individuals. All prey items belonged to class Actinopterygii. Overall, 12 fish prey were identified (2 at the family, 3 at the genus and 7 at the species level). Razorbills fed on small-medium sized fish species of the neritic zone such as Belone belone, Trachinotus ovatus, Atherina hepsetus and Engraulis encrasicolus. Razorbills were mostly observed foraging close to the coast and within harbours, as well as begging for food from humans, raising doubts about the feeding conditions encountered and the health status of individuals. Dead individuals mainly had empty stomachs, in line with the low weights and fat scores detected during necropsy. We underline how data from social media have made it possible to describe, using non destructive methods, the behaviour and feeding habits of an uncommon seabird typical of the North Atlantic Sea, which caught the attention of photographers, nature enthusiasts, and scientists.

Infection of Kudoa anatolica (Cnidaria: Myxozoa): Impact on the Nutritional Composition of Atherina hepsetus (Atherinidae) Flesh

ABSTRACT Mediterranean sand smelt Atherina hepsetus, whose flesh was infected by Kudoa anatolica, was investigated for its impacts on the nutritional composition of host fish. Based on the infection densities of K. anatolica, fish were grouped to have uninfected control (A), slightly (B), moderately (C), and highly infected (D). While there were no significant changes in the crude protein (CP), crude lipid (CL), and energy contents (p > .05), significant changes were determined in the total amino acid content between groups (p < .05). The present study proved changes in the proximate, fatty acid, and amino acid composition in flesh and the negative impacts of a Kudoa species.

FINDING OF TWO FISH SPECIES IN THE HYPERSALINE WATERS OF THE SIVASH BAY (SEA OF AZOV)

During a number of years juveniles and larvae of Atherina boyeri Risso, 1810 and Knipowitschia caucasica (Berg, 1916) were caught in the hypersaline waters of Sivash at salinity up to 70-75%. Once the larvae of Atherina hepsetus Linnaeus, 1758 at a salinity of 54% and A. boyeri at a salinity of 90% were caught. New data on the expansion of the salinity range of the survival of A. boyeri are presented.

Age, growth, reproduction and mortality of Mediterranean sand smelt Atherina hepsetus (Atherinidae) from the Crimea region (the Black Sea)

Sex ratio, size and the age structure, growth, dynamics of gonadosomatic indices and mortality were analyzed for the Mediterranean sand smelt Atherina hepsetus collected in the Crimean coastal area. Overall, 3193 specimens were examined between 2011 and 2021 years. The total sex ratio in the A. hepsetus catches was balanced (1.03:1), but it differed in the older age groups, where females predominate. The maximum total length of females was 15.8 cm, of males was 15.6 cm; its weight was 26.6 g and 23.6 g, respectively. The maximum age for both sexes was 4 years. There was not any statistical difference in sizes and growth between sexes. The values of the parameters of the Bertalanffy equation were calculated: in females, the asymptotic length was 15.94 cm, the asymptotic weight was 25.98 g, the growth constant was 0.53 year −1; for males — 15.90 cm, 24.47 g, and 0.55 year −1, respectively. The exponent values of the length–weight relationships in females was 3.09, in males – 2.96. The growth performance index in females was 2.13, for males — 2.14. Spawning period falls in March–July with the peak in April. The total and fishing mortality rates for both sexes were 1.52 year −1, 1.07 year −1 and 0.45 year −1, respectively; the exploitation ratio was 0.30, that indicated a low fishing pressure. It has been found that Atherina hepsetus from the Crimean waters differs from the Mediterranean Sea populations for the largest sizes and the highest growth rate.

Marmara Denizi’nde Gümüş Balığı (Atherina hepsetus Linnaeus, 1758) Popülasyonunun Bazı Biyolojik Özellikleri Üzerine Bir Araştırma

Bu çalışmada, Ocak-Mart 2017 tarihleri arasında Marmara Denizi Gemlik Körfezi’nden yakalanan 213 adet gümüş balığı (Atherina hepsetus L.) bireyinde morfometrik ilişkiler, sağ ve sol premaksil kemik özellikleri, boy ve ağırlık dağılımları, boy-ağırlık ilişkisi ve kondisyon faktörü belirlenmiştir. Yakalanan örneklerden 24 adet metrik ve meristik ölçüm elektronik kumpasla yapılmış aralarındaki ilişkiler hesaplanmıştır. Çalışmada elde edilen örneklerin total boy ve ağırlıkları sırasıyla 99-145 mm ve 6,4-18 g arasında dağılım göstermektedir. Tüm örnekler için boy-ağırlık ilişkisi W=0,012L2,74 ortalama kondisyon faktörü değeri ise 0,65 olarak hesaplanmıştır. Türün sistematiğinde kullanılan premaksil kemiklerinin sağ ve sol çiftlerinin biyometrik özellikleri farklı eksenler üzerinde belirlenmiştir.

Effect of Frozen Storage on the Chemical Composition of Sand Smelt (Atherina hepsetus) Fish Burger and Finger

Sand smelt fish (Atherina hepsetus) one of the low economic fish and unacceptable from consumers in Qarun lake, Egypt. Sand smelt fish burger and finger made from sand smelt fish with soybean flour (SF) and minced boiled potatoes (MBP) to improve the economic value for fish. Changes in proximate composition of sand smelt fish products during frozen storage were determined. Chemical analysis indicated that moisture, protein and fat contents of burger and fingers samples gradually decreased during frozen storage period while ash and carbohydrate contents increased during frozen storage. No considerable changes in cooking loss could be observed in the early stages of frozen storage. Meanwhile, as the storage period prolonged, cooking loss values increased. The filling materials SF and MBP used in the production of fish products showed an observed effect in maintaining the chemical composition of the products for 90 days of frozen storage. It can be concluded that sand smelt fish products opening an opportunity for this good nutritious protein source to be used as a daily food.

Variability of Otolith Morphology and Morphometry in Eight Juvenile Fish Species in the Coastal Eastern Adriatic

AbstractSagittae otoliths of eight juvenile species:Boops boops,Diplodus vulgaris,Diplodus puntazzo,Sarpa salpa(family Sparidae),Liza ramada,Liza aurata(family Mugilidae),Atherina boyeri,Atherina hepsetus(family Atherinidae) were analysed and compared using descriptive morphological characters and morphometric indices. The noticeable differences among the otoliths of the investigated species are in their overall shape, margins (i.e. irregular, sinuate or crenate) and anterior region. Otolith shape varied from elliptic to pentagonal in sparids, elliptic to rectangular in mugilids and elliptic in two atherinids. Aspect ratio (OW/OL), ratio of the sulcus length occupied by the cauda length (CL/SL) and ratio of the sulcus length occupied by the ostium length (OSL/SL) were calculated for all species. The otolith contour was described using wavelets. The Canonical Analysis of Principal Coordinates (CAP) gave an overview of the otolith shape differentiation between eight juveniles. Using the Wavelet coefficients, the first principal component (CAP1) explained 58.1% of the variation among species and the second principal component (CAP2) 25.2%.

Changes in quality attributes of sand smelt (Atherina hepsetus) fish burger and finger during frozen storage.

The present investigation has been carried out with the objectives study the effect of frozen storage on quality attributes of fish burger and fingers were made from sand smelt (bassaria) (Atherina hepsetus) with substitution levels from soybean flour and minced potato. Sand smelt has found in Qarun Lake by unaccepted from consumers. The physicochemical and microbiological analysis was carried on raw products immediately after processing and during frozen storage.Total Volatile Basic Nitrogen (TVBN), Trimethylamine (TMA), Thiobarbituric Acid (TBA) and pH values of sand smelt fish products showed significant increase during frozen storage for 3 months except pH value. Quality attributes parameters values of control samples were higher than those with substitution levels by soybean flour and minced potato. Sand smelt fish burger and finger made from sand smelt fish maintained on their good quality parameters until end of storage period.

Otolith shape analysis and mitochondrial DNA markers distinguish three sand smelt species in the Atherina boyeri species complex in western Mediterranean

Atherina boyeri is a common euryhaline teleost fish in the Mediterranean and adjacent areas, which inhabits coastal and estuarine waters, including coastal lagoons and more rarely inland waters. Several recent studies have pointed the possible existence of three distinct groups or species, one lagoon/freshwater group and two ‘punctuated and unpunctuated on the flanks' marine groups, within an A. boyeri species complex. This study is a combined approach using otolith shape and molecular markers to better define the structure of the species in the western Mediterranean.Genetic differentiation and species delimitation among nine Atherina boyeri populations from several marine and lagoon/brakish habitat sites in Algeria, Tunisia and France were investigated using three mitochondrial (control region, Cyt b and 16S) and one nuclear markers (2nd intron of S7). For further phylogenetic and phylogeographic study, we added sequences from Genbank covering more areas (Ionian Sea, Adriatic Sea, Tyrrhenian Sea, Black Sea, Atlantic). Five groups were found. Two of them perfectly corresponded to two species already recognized Atherina presbyter and Atherina hepsetus, both living in marine waters; and three additional, including Atherina boyeri (brackish and freshwater environments) and two independent groups of marine punctated and unpunctated individuals. Those findings are corroborated by the study of the otolith contour shape of 362 individuals of seven populations from different habitats using Fourier analysis. Individuals could be discriminated into five groups based on the first two functions (Wilk's lambda = 0.07, p < 0.001). Samples from Ziama inlet, marine punctuated individuals and unpunctuated marine specimens from Annaba's Gulf formed three well separated groups. Specimens from Mellah and Mauguio lagoons formed another group. The last one includes individuals from Bizerte and Thau lagoons. The divergences between them strongly support the potential species within the A. boyeri species complex.

Репродуктивные показатели и экология размножения атлантической атерины Atherina hepsetus (Pisces: Atherinidae) у западного побережья Крыма

Атерины (сем. Atherinidae) — массовые представители прибрежной пелагической ихтиофауны Азово-Черноморского бассейна, в некоторых районах являются объектами промысла. Вместе с тем сведения о биологии и экологии атерин до настоящего времени остаются крайне скудными и фрагментарными. Данная работа посвящена изучению меж- и внутригодовой (сезонной) изменчивости ряда индивидуальных и популяционных репродуктивных показателей атлантической атерины Atherina hepsetus из акватории Черного моря, прилегающей к западному побережью Крыма. Отлов производился ставными неводами круглогодично в течение 2010–2014 гг. с периодичностью 2–3 раза в месяц. В общей сложности изучено 2403 экз. На основе результатов исследования впервые введены понятия общего, популяционного и массового (пик нереста) репродуктивных периодов, установлены межгодовые изменения их продолжительности, а также календарные сроки начала и окончания. Изучены интенсивность нереста и его сезонная динамика, сезонная динамика развития половых желез самцов и самок и определены индивидуальные и среднепопуляционные значения их гонадосоматического индекса. Установлен диапазон изменчивости температуры нереста (8.5–14.5 ℃), выделена зона максимально благоприятной нерестовой температуры (9.0–12.0℃).

Some Morphological Characters of Female of Mothocya epimerica Costa, 1851 (Flabellifera: Cymothoidae) from Sea of Marmara

Abstract Mothocya epimerica Costa, 1851 (Flabellifera: Cymothoidae) is a cymothoid parasite of fishes belonging to Atherinidae (Atherina hepsetus, Atherina boyeri) from Mediterranean Sea, Black Sea and Atlantic Ocean. Öktener and Sezgin (2000) recorded this parasite for the first time in Turkey. The mentioned authors presented some morphological characters, although, some characters are not explained in the publication. Some morphological characters seen on the mandible, maxilliped, maxilla, maxillue and the spines on pleopods of the female of M. epimerica are shown. The characters presented in our study are based on the drawings made from collected specimens.

Damages on mussel farms potentially caused by fish predation—Self service on the ropes?

A dramatic decline has been recorded in Croatian shellfish production in recent years. Among the many factors that may have contributed to the decline of mussel production, i.e. EU import barriers and consequently small domestic market, great variability in larval dispersion and settlement, it is suspected that fish predation plays an important role in shellfish sustainability. Following this hypothesis, the abundance and diversity of fish assemblages around the Marina mussel farm, situated along the eastern coast of the Adriatic Sea, was monitored for a two-year period, and the mussel recruitment losses, potentially driven from fish predation, after the ‘early thinning-out’ process was quantitatively evaluated by measuring the percentage of consumed or destroyed ropes of longlines. Overall, a total of sixteen fish taxa were recorded at the mussel farm, as opposed to fifteen taxa registered at all control locations. The asymmetrical design of the multivariate analyses revealed a statistically significant impact of the farm on fish assemblages, with expressed seasonal species variation. At mussel farm, the most abundant species observed were gilthead seabream Sparus aurata, sand smelt Atherina hepsetus and mullet Mugilidae species in summer and autumn; sand smelt A. hepsetus and bogue Boops boops in winter; and the sand smelt A. hepsetus, mullet Mugilidae species and seddled bream Oblada melanura in spring. At control locations, characterised with significantly lower fish assemblage abundances, the most abundant species were sand smelt A. hepsetus and mullet Mugilidae species in summer, sand smelt A. hepsetus and seddled bream O. melanura in autumn, sand smelt A. hepsetus and picarel Spicara flexuosa in winter, sand smelt A. hepsetus and bogue B. boops in spring. Gilthead sea bream was extremely abundant at mussel farm, with 5936 individuals censused in 155 of 192 fish counts (80%), and a maximum abundance of 285 individuals per 5000 m 3. Stomach content analysis confirmed the presence of mussel Mytilus galloprovincialis as the dominant prey. During August (2009), monitoring of 423 ropes revealed that 276 m of mussel ropes or approximately 828 kg of mussels with an average shell length of 34.3 ± 2.54 mm were destroyed within the first week of mussel deposition into the sea. The recorded recruitment losses of 54% in only one month of monitoring indicate a strong negative impact on farm management stability.

Multilocus phylogenetic analysis of the genus Atherina (Pisces: Atherinidae)

Sand-smelts are small fishes inhabiting inshore, brackish and freshwater environments and with a distribution in the eastern Atlantic and Mediterranean Sea, extending south into the Indian Ocean. Here, we present a broad phylogenetic analysis of the genus Atherina using three mitochondrial (control region, 12S and 16S) and two nuclear markers (rhodopsin and 2nd intron of S7). Phylogenetic analyses fully support the monophyly of the genus. Two anti-tropical clades were identified, separating the South African Atherina breviceps from the north-eastern Atlantic and Mediterranean Atherina’ species. In European waters, two groups were found. The first clade formed by a well supported species-pair: Atherina presbyter (eastern Atlantic) and Atherina hepsetus (Mediterranean), both living in marine waters; a second clade included Atherina boyeri (brackish and freshwater environments) and two independent lineages of marine punctated and non-punctated fishes, recently proposed as separate species. Sequence divergence values strongly suggest multiple species within the A. boyeri complex.

Discards of the commercial boat seine fisheries on &lt;i&gt;Posidonia oceanica&lt;/i&gt; beds in the eastern Adriatic Sea

Scientific observer records were used to estimate the retained and discarded catch composition of the commercial boat seine fisheries over Posidonia oceanica (Linnaeus) Delile meadows in the eastern Adriatic, from November 2008 to December 2009. A total of 91 fish and cephalopod species were recorded in the catches, of which 20 species were always retained, 40 were always discarded and the remaining 31 were selected depending on size (only larger specimens were retained). The most abundant species in the retained catch were Spicara smaris , Atherina hepsetus and Mullus barbatus , while Chromis chromis, Symphodus ocellatus and small specimens of Boops boops dominated the discards. An estimated 43.5% by number and 28.5% by weight of the total catch were discarded. Since the minimum landing size (MLS) is regulated for only 4 out of the 15 most important species in this study, and even these regulations are only partially followed, discarding practices were generally market-driven. The retained and discarded amounts of the catch as well as the numbers of retained and discarded species showed a seasonal pattern. The catches recorded during summer/autumn were generally larger than those in winter/spring. High rates of immature specimens were observed for the most important species, which is probably related to the role of Posidonia beds as important nursery grounds.

Mitochondrial DNA in Atherina (Teleostei, Atheriniformes): differential distribution of an intergenic spacer in lagoon and marine forms of Atherina boyeri

The big‐scale sand smelt Atherina boyeri lives in fresh water, brackish water and sea water of the western Atlantic Ocean and Mediterranean Sea. Previous studies concerning distribution, biometric characters and genetic molecular markers have suggested the possible existence of two or even three different groups or species of sand smelt, one ‘lagoon’ type and one (or two – punctuated and non‐punctuated on the flanks) ‘marine’ type. In this study, the presence and the localization of an insertion was described, c. 200 bp in length, in the mtDNA of the lagoon and marine punctuated specimens of A. boyeri and its absence in the marine non‐punctuated specimens, as well as in other two congeneric species, Atherina hepsetus and Atherina presbyter, and in the atheriniform Menidia menidia. The intergenic spacer is located between the tRNAGlu and cytochrome b (cyt b) genes and shares a c. 50% sequence similarity with cyt b. The distribution and the features of the intergenic spacer suggest that it might have originated from an event of gene duplication, which involved the cyt b gene (or, more likely, a part of it) and which took place in the common ancestor of the lagoon and the marine punctuated specimens. The data obtained therefore support the hypothesis of the existence of three cryptic and, or sibling species within the A. boyeri taxon and provide a genetic molecular marker to distinguish them.

Genetic diversity of Atherina hepsetus (Osteichthyes: Atherinidae) populations as determined by RFLP analysis of three mtDNA regions

The genetic differentiation of 11 Greek Atherina hepsetus populations have been investigated at the mtDNA level. Restriction fragment length polymorphism analysis of three mtDNA regions (12S rRNA, 16S rRNA and D‐loop) amplified by PCR was used. Eighteen restriction endonucleases were found to have at least one recognition site at the three mtDNA regions studied. Fifteen different composite haplotypes were detected among the populations studied while 80.6% of the individuals were grouped in two common haplotypes. The estimated net nucleotide sequence divergence values between the populations ranged from 0.003 to 0.379%, while the Nst value of 0.092 indicates the existence of low interpopulation genetic differentiation. The findings clearly support the existence of a single panmictic population in the sampling area.

Natural Occurrence of Metallothioneinlike Proteins in Liver Tissues of Four Fish Species from the Northeast Mediterranean Sea

Fish with different ecological needs were captured from the northeast Mediterranean Sea to determine metallothioneinlike proteins in their livers. Heat-treated liver samples were run on a column packed with Sephadex G-75 (Sigma, Germany) for subsequent determination of metals, sulfhydryl, and absorbance at 254 and 280 nm. Liver cytosols of Sparus auratus and Mullus barbatus had three heat-stable protein peaks, whereas Mugil cephalus and Atherina hepsetus had two. The third protein peak, containing metallothionein-like proteins (5000 to 6000 Da), was present in all fish. Only high- and low-molecular-weight proteins contained sulfhydryl and metals. Zinc was the most abundant metal in the metallothioneinlike proteins, whereas cadmium and lead were not detected. The differences in the characteristics of metal-binding proteins among fish indicate that the biological characteristics of fish species should be carefully taken into account concerning natural monitoring studies.

Phylogenetic relationships of Atherina hepsetus and Atherina boyeri (Pisces: Atherinidae) populations from Greece, based on mtDNA sequences

The genetic divergence and the phylogenetic relationships of six Atherina boyeri (freshwater and marine origin) and five Atherina hepsetus populations from Greece were investigated using partial sequence analysis of 12s rRNA, 16s rRNA and control region mtDNA segments. Three different well divergent groups were revealed; the first one includes A. boyeri populations living in the sea, the second includes A. boyeri populations living in the lakes and lagoons whereas the third one includes all A. hepsetus populations. Fifty-seven different haplotypes were detected among the populations studied. In all three mtDNA segments examined, sequence analysis revealed the existence of fixed haplotypic differences discriminating A. boyeri populations inhabiting the lagoon and the lakes from both the coastal A. boyeri and the A. hepsetus populations. The genetic divergence values estimated between coastal (marine) A. boyeri populations and those living in the lagoon and the lakes are of the same order of magnitude as those observed among coastal A. boyeri and A. hepsetus populations. The results obtained by different phylogenetic methods were identical. The deep sequence divergence with the fixed different haplotypes observed suggests the occurrence of a cryptic or sibling species within A. boyeri complex. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92, 151–161.

Diel catch variations in a shallow-water fish assemblage at Duće Glava, eastern Adriatic (Croatian Coast)

An assemblage of shallow-water fish was sampled with a small beach seine over monthly 24-h periods between April 2000 and March 2001 at the sandy beach Duće Glava in the eastern Adriatic. Monthly sets of samples were divided into day and night catches to examine the stability of diel differences in assemblage structure over a 1-y period. A total of 61 species was caught, of which six were exclusively diurnal and 12 were nocturnal. According to abundance and biomass of individuals during day and night, the most abundant species were categorized into several groups. Ophidion rochei was exclusively nocturnal, while Nerophis ophidion and Echiichthys vipera were mostly nocturnal. Diplodus annularis and Mullus surmuletus were slightly nocturnal. Diplodus vulgaris, Pomatoschistus marmoratus and Atherina boyeri lacked a diel pattern. Sardina pilchardus, Lithognathus mormyrus, Atherina hepsetus, Sarpa salpa and Mullus surmuletus abundance peaked for a few months, probably related to timing of spawning and recruitment. At the assemblage level, the diel per cent similarity index indicates that there were major differences between the day and night assemblages in April, September, March, and August with respect to number of individuals and September, October, May and March with respect to biomass.