Exploring the relationship between larvae abundance and individual caribou health R.A. Been Faculty of Veterinary Medicine Utrecht University July until September 2011 Abstract It is known that gastrointestinal nematodes can have a significant impact on the growth of farmed ruminants. The clinical signs are often subtile, but production losses can be of big importance. Little is known about the impact of gastrointestinal nematodes in wild ruminants. I used cross-sectional data to explore the relationship between larvae abundance and individual caribou health. Being part of a two year master project, I evaluated results of 18 samples of adult caribou from the Akia-Maniitsoq herd, isolating larval nematodes from the mucosal lining of the abomasa using a pepsin-HCl digestion. The goal of this study was to discover a relationship between mucosal larvae abundance and caribou health condition. This study did not discover a relationship unfortunately, but these results are preliminary as this study is part of a two year project. Introduction Natural and translocated populations of caribou and semidomesticated Norwegian reindeer (Rangifer tarandus spp.) are present along the west coast of Greenland from the southern peninsula to Inglefield Land in the north, see figure 1. My work focuses on the one of the two largest herds in west Greenland, Akia-Maniitsoq (AM). The herd inhabits a semi-isolated range due to the Greenlandic ice cap to the North and extensive fjord system to the south. The Northern people traditionally have a close relationship with caribou. Caribou are the basis of their cultures and still play a central role in their lives, caribou are harvested annually for meat and outfitting (Albon et al., 2002; Melgaard, 1986; Stien et al., 2002). KS collection sites KS herd range AK collection sites AK herd range Austmannadalen region Historical Norwegian reindeer range Figure1. Ranges of native and imported species of interest in west Greenland Caribou are grazers that include a wide variety of plants in their diet, but eat most lichen and sedges. During foraging they might also ingest different kinds of gastrointestinal parasites through fecal contamination of pastures (Albon et al, 2002; Stien et al., 2002). This could include parasites from semi-domesticated Norwegian reindeer (Rangifer tarandus tarandus) and domestic sheep (Ovis aries), which were imported into ranges adjacent to AM. (Melgaard, 1986). The goal of this study was to define a relationship between larvae abundance and individual caribou health. My work is part of a bigger two year master project. I hypothyse that caribou health is negatively associated with larvae abundance, as it is generally accepted that gastro intestinal parasites can have negative effects on individuals in relation to the individual’s health. In the herd of caribou the following groups of parasites were identified through fecal analysis: nematodes (identified by the presence of Trichostrongylid-type, Marshallagia spp. and Nematodirine eggs) and cestodes (eggs present are most likely Moniezia spp.). The nematode lifecycle can involve a stage of inhibition delaying maturation of ingested 3rd stage larva into reproductive adults, occurring during unfavourable conditions for eggs on pasture, e.g. winter or dry seasons. (Hoar et al., 2009; Smith, 1979). This delays the release of eggs until pasture conditions favour egg survival and development, such as warmer temperatures during spring. This resumption has effects on animal health as emerging larvae cause gross damage to the gastric glands of the abomasums where they sequester during inhibition. Documented clinical effects of type II Ostertagiasis, in domestic species include diarrhea, leading to a decrease in body weight and mortality. (Albon et al, 2002; Stien et al, 2002; Hughes et al., 2009) Procedure Female caribou and their calves-at-heel were collected opportunistically as part of the CircumArctic Rangifer Monitoring and Assessment (CARMA) Network initiatives. Collections occurred from Mar. 29 to Apr. 13, 2008. Sample collections from mature animals (≤ 1 year), including the removal and freezing of the abomasa, occurred within a few hours of caribou being shot (Russell et al., 2010). I isolated larval nematodes from the mucosal lining of the abomasa of 18 adult female caribou using a pepsin-HCl digestion (Appendix 1). This is a quantitative technique, allowing us to estimate larval nematode intensity (Eysker, 1999). Results and discussion All of the 18 adult female caribou examined in this cross-sectional study were parasitized by abomasal nematodes. My work only contains adult animals as I had limited time to do all digestions and analysis of the samples needed to be able to discover a relationship between mucosal larvae abundance and caribou health condition. Testing for negative effects of nematodes on caribou health condition in this study is difficult because both small sample size and the variation among samples (animal age, body mass, body condition) can add to the error variance. (Gunn, 2008; Stien et al. 2002) Because in this study there were only adult samples analyzed, there are several points in time missing, for example the time span wherein the calves immune response develops is not covered in this study. This research is part of a bigger Masters project at the University of Calgary (by Jillian Steele), the results that were available at the time this paper was written are only preliminary results for the bigger project that will also cover other age classes of caribou. The final research will contain the results of caribou from two adjacent herds, Akia-Maniitsoq (AM) and Kangerlussuaq-Sissimiut (KS). In total there will be results from 40 AM samples and 33 samples from KS. I will discuss my results out of the 18 adult samples in comparison with previous work that was done, there is no statistical analysis of the results included as my data have shown no statistical significance, most likely due to the small sample size. (Appendix II) Nematode demographics Nematode demographics were estimated by analyzing the abomasal digests as described in the procedure. The abomasa were collected during post-mortem examination in the spring of 2008. Results estimated from abomasal digests The results of the abomasal digests showed that the larva abundance varies between 265 and 2000 larvae per caribou. It also shows that intensity of infection with larvae in the abomasal mucosa rises when the host age increases. There was one animal that differed a lot from the others; this animal had a mucosal larvae count of 2000 larvae. Previous research has confirmed that nematode abundance increases with host age, reaching asymptotic levels at 2-4 years of age for O. gruehneri and at about 4 months of age for M. marshalli (Halvorsen et al.,1999; Irvine et al,. 2000). The results found in this study showed no statistical correlation for nematode abundance and caribou age, but this might be due to the small sample size and the small variation in the adult age class. Relation to body condition In wild ungulates fat reserves are widely accepted to be a good reflection of general body condition, and we assessed possible relations between these, general body parameters (e.g. body weight), reproductive status and larval nematode abundance. (Allaye Chan-McLeod et al., 1995) Body weight Previous work has shown a significant decrease in body weight with increasing abundance of mucosal larvae, and this effect was exaggerated in non-pregnant animals of the population. (Halvorsen & Bye 1986, 1999). In this study I found no correlation between larva abundance, body weight and pregnancy, but as body weights are highly variable with respect to age and season of the year, we likely need to add more parameters to the assessment. Back fat Back fat depth is considered a reliable indicator of ungulate health condition, it is generally considered better than weight since weight depends on animal size as well (Gerhart et al., 1996). Moreover, Adamczewski et al. (1987) found that the relation between total dissectible fat and depth of back fat is linear or near-linear in Rangifer, this shows that the use of back fat is a good index for total body fat. In this research no relation was found between measures of back fat depth and larva abundance. This is similar to results found by Huges at al., 2009 and Stien at al., 2002. Back fat is the first fat reserve to be used during malnutrition; therefore there is no correlation below 6% total body fat, which as all our animals are in poor body condition, may be the case. Riney kidney index Visceral fat is deposited around the internal organs, such as kidneys, in ungulates when food availability is good. The Riney kidney index (RKI) is proven to have good correlation with dissectible fat, moreover at the low range of body condition it is expected to be a good index. The use of the RKI which compares kidney and kidney fat weight, has been criticized as kidney weights may fluctuate during the year, by Batcheler and Clarke 1970; Dauphine 1975. Our samples were collected during spring 2008, all samples were collected during the spring so the fluctuation of kidney weight during the year should not be of importance, since all samples were collected in the same time of year. We found no correlation between larva abundance and kidney fat, which is surprising as the RKI works well in animals with low fat reserves, making it preferred over back fat depth (Riney, 1955). Kidney fat is more mobile than marrow fat, so when condition of the caribou declines, kidney fat will deplete first, before other fat depositions will be used (Kie, 1988). This points out that when an animal has no kidney fat, it might still be in a condition to survive and reproduce. It is important to realize that it will probably have other effects on the animals health condition, those effects will not be discussed here. Riney kidney index values can range from a low of only a few percent, representing solely connective tissue and no fat, to over 100 percent. The animals in this study were all in a range between 18 and 136 % RKI, with an average of 54%. Bone marrow fat Bone marrow fat is known to have a good correlation with body fat in thin, starving animals. Since all our animals are in poor condition, one might expect to find a relationship between bone marrow fat and larva abundance. In this study I did not find a relationship between bone marrow fat and larva abundance, which could also be a result of the small sample size. (Kie, 1988; Neiland 1970). Future research Testing for relations between nematodes and caribou health in this study is challenging because of both the small sample size and the variation among samples (animal age, body mass, body condition) which can add to the error variance in small sample sizes. It is also complicated by our lack of knowledge of nematode abundances and host health over a period of time, as body condition is not affected by current nematode abundance, but rather the burden of past times (Stien et al., 2002). There are several other reasons for this cross sectional study not detecting parasite impacts on caribou body condition. First, both negative and positive relationships are possible. For example, body mass may be negatively related to worm burden but fitter individuals such as those that have become pregnant may have higher worm burdens. Second, individuals that eat more may have more parasites and therefore may be heavier, in better condition and better able to withstand high parasite loads. Some of these problems can be overcome by conducting experiments that manipulate parasite loads which allows a direct test of the impact of parasites on host body condition scores (Côte et al., 2005; Hutchings, 2001; Stien et al., 2002). As my work contains only adult animals, future work is needed with a larger sample size and more complex models covering other age classes of caribou; sub-adults and calves. This would let us examine the time span wherein the immune response develops which is not covered in this study. Other considerations regarding our results include other factors influencing the health of the animal as well, for example the time of year, animal diseases and availability of food. Second is that in this study there was no differentiation between the different nematode species, previous work has shown that the different species vary in the time of year when their abundance peaks. Acknowledgements I want to thank Deborah van Doorn from Utrecht University for her assistance from the Netherlands and for giving me the opportunity to fulfill my research project on the subject of parasitology. I want to thank dr. Susan Kutz, dr. Karin Orsel and Jillian Steele from the University of Calgary for the opportunity to do my research project at their university. James Wang for always helping me out with troubles in the lab, Robbert Huggins for his help in the statistical part of this research, Marianne Vervest and Cynthia Kashivakura for the fun times in the lab and last but not least Barb Cowley for her great hospitality, thanks to them all I had a very nice time working and living in Calgary. References Adamczewski, J. Body composition in relation to seasonal forage quality in caribou (Rangifer tarandus groen-landicus) on Coats Island, Northwest Territories. MSc., 1987 U. Alberta Albon, S.D., Stien, A., Irvine, R.J., Langvatn, R., Ropstad, E. & Halvorsen, O. The role of parasites in t he dynamics of a reindeer population. Proceedings of the Royal Society Biological Sciences Series B, 2002, 269(1500): 1625-1632. Allaye Chan-McLeod, A.C., White, R.G., Russel, D.E. Body mass and composition indices for female Barren-Ground caribou. The Journal of Wildlife Management, 1995, 59(2), p.278-291) Côte, S.D., Stien, A., Irvine, R.J., Dallas, J.F., Marshall, F., Halvorsen, O., Langvatn, R., Albon, S.D. Resistance to abomasal nematodes and individual genetic variability in reindeer. Molecular Ecology, 2005, 14(13), p. 41594168 Eysker, M., Klei, T.R., Mucosal larval recovery techniques of cyathostomes: can they be standardized? Veterinary Parasitology, 1999. 85, p. 137–149 Gerhart, K.L., White, R. G., Cameron, R. D., Russell, D. E. Estimating Fat Content of Caribou from Body Condition Scores The Journal of Wildlife Management, 1996, 60 (4), p. 713-718 Gunn, A., Nixon, W., eds. Monitoring Protocols - Level 2. Rangifer health and body condition monitoring, ed. CARMA. 2008, p. 54. Halvorsen, O., Stien, A., Irvine, J., Langvatn, R. & Albon, S. Evidence for continued transmission of parasitic nematodes in reindeer during the Arctic winter. International Journal of Parasitology, 1999. 29, p. 567-579 Hoar, B., Oakley, M., Farnell, R., Kutz, S., Biodiversity and springtime patterns of egg production and development for parasites of the Chisana Caribou herd, Yukon Territory, Canada. Rangifer 2009. 29 (1), p. 25 – 37. Hughes, J., Albon, S.D, Irvine, R.J., Woodin, S., Is there a cost of parasites to caribou? Parasitology, 2009. 136, p. 253-265 Hutchings, M. R., Kyriazakis, I., Gordon, I. J., Herbivore Physiological State Affects Foraging Trade-Off Decisions between Nutrient Intake and Parasite Avoidance. Ecologie, 2001. 82 (4), p. 1138-1150. Irvine, R.J., Stien, A., Halvorsen, O., Langvatn, R., Albon, S.D. Life-history strategies and population dynamics of abomasal nematodes in Svalbard reindeer (Rangifer tarandus platyrhynchus). Parasitology, 2000, 120(3), p. 297-311. Kie, J.G., Performance in Wild Ungulates: Measuring Population Density and Condition of Individuals (1988) Korsholm, H., Olesen, C.R., Preliminary investigations on the parasite burden and distribution of endoparasite species of muskox (Ovibos moschatus) and caribou (Rangifer tarandus groenlandicus) in West Greenland. Rangifer 1993. 13 (4), p. 185-189. Melgaard, S., Bentounsi, B., Zouyed, I. and Cabaret, J. The Greenland Caribou – Zoogeography, Taxonomy, and Population Dynamics, Kommissionen for Videnskabelige Undersøgelser I Grønland, Copenhagen. 1986, 88pp. Riney, T. Evaluating condition of free-ranging red deer (Cervus elaphus) with special reference to New Zealand. New Zealand Journal of Science, 1955. 36, p. 429-463. Russell, D., CARMA Network. 2010; Available from: http://www.carmanetwork.com. Smith, H.J., Observations on the resumption of development of inhibited Ostertagia, Cooperia and Nematodirus infections in calves stabled overwinter. Canadian Journal of Veterinary Research 1979. 43(4), p. 434–439. Steele, J., Risk factors associated with parasite abundance and host translocation in West Greenland caribou. AINA Grant-in-Aid proposal, 2011. Stien, A., R.J. Irvine, E. Ropstad, O. Halvorsen, R. Langvatn, and S.D. Albon. 2002. The impact of gastrointestinal nematodes on wild reindeer: experimental and cross-sectional studies. Journal of Animal Ecology 71:937. University of Calgary, Canada, Standard Operating Procedure. Addendum Appendix l University of Calgary Department of Veterinary Medicine Standard Operating Procedure Procedure Title: Method for digesting abomasa to quantify larval nematodes Minimum Review Requirements: Yearly Creation Date: 30 May 2011 Date of Next Review: 30 June 2011 Administrator of Procedure: Supervisor of Procedure: Authorized by: Table of Contents Title Page and Table of Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Version History ...................................................................................................... 8 Introduction ........................................................................................................... 1 Definition ................................................................................................................ 8 Personnel ................................................................................................................ 8 Safety ...................................................................................................................... 8 Procedure ............................................................................................................... 3 Equipment or Materials Required ..................................................................... 10 Highlights / Critical Control Points ................................................................... 10 Reporting.............................................................................................................. 10 Regulatory / Standards ....................................................................................... 10 Trouble Shooting ................................................................................................. 10 References ............................................................................................................ 10 1. Version History Version #: Supersedes: 1.1 n/a The signatures below indicate the person(s) responsible to administer and supervise this procedure have read and agree toabide by the SOP attached Date Handwritten amendments to the official procedures can be made by a single line through the text, along with the date, and initialed by the authorized individual making the correction. Changes are to be noted below. Formal changes to thisSOP are made on the date of revision or sooner, where required. Section Changes made to official copy Date Initials 2. Introduction This technique is used to isolatelarval nematodes from the mucosal lining of the abomasa. This is a quantitative technique and can be used to produce estimates of larval nematode burden and specimens for identification of species composition. 3. Definition N/A 4. Personnel SOP issued under authority of: Persons authorized to perform The SOP: Dr. S. Kutz, Jian Wang All lab staff 5. Safety Abomasa to beprocessed are of unknown pathogenicity (bacterial, fungal, viral and parasitic pathogens are all possible).Proper biosafety procedures should be followed for this process. These include: - Always wearing PPE (gloves and a lab coat) in exposure situations - Abomasal tissue should be disposed in a black garbage bag, double bagged - Bags should either be taken for incineration immediately or placed in the freezer to be incinerated at a later date - HCL is a highly corrosive chemical and great care should be taken not to spill, imbibe or inhale it - If any personal exposure occurs proper first aid and biosafety procedures for such an incident should be followed - All waste should be disposed of in the appropriate liquid waste container - All tools and equipment should sit in a Vircon solution (10g/L) for at least 10mins before being cleaned with soap and water and then disinfected with ethanol - Wash hands and forearms after performing the diagnostic test As this procedure also involves using surgical equipment (carving knifes/ metal depressor), care should also be taken not to cut oneself. If a wound is caused with the equipment proper first aid and biosafety procedures for such an incident should be followed. 6.Procedure 6.1 Remove abomasa from freezer and place in a small tray; allow to defrost 6.2 Mix together pepsin-HCl solution in an Erlenmeyer (thin-necked) Flask - Small abos (caribou) will need 1L, large abo (muskox) 1.5L - Can be done in fume hood if technician is sensitive to HCl - 500ml; 4g pepsin / 4.25g NaCl / 10mL HCl / Distilled H2 6.3 Place thawed abo. into the flask and seal with parafilm 6.4 Incubate the flask in a shaking incubator for 1.5hr at 39°C 6.5 Mix together another 500mL of pepsin-HCl solution 6.6 Remove flask from incubator and place the abo. on the plastic tray 6.7 Using a blunt metal depressor (or knife) scrape the mucosa off the musculature - Should render the abo. almost see-through if done correctly 6.8 Rinse the abo., tools and your gloves with the extra pepsin-HCl solution and pour this and the mucosalscrappings back into the flask - Should rinse at least twice, or until volume in flask is ~1.5L (if started with 1L) - Abo. can now be discarded 6.9 Reseal the flask and place it back into the incubator for another 2-3hr at 39°C or until large abo. chunks are dissolved 6.10 Remove the flask, and pour contents into a large mouthed beaker. Add distilled water to bring volume up to a multiple of 500mL (e.g. 1L / 1.5L / 2L) 6.11 Take two 10% aliquots from the beaker - While holding a sample cup, agitate the contents with your gloved hand - In one go, remove 10% (e.g. 100mL / 1L; 150mL / 1.5mL) - If excess is pulled up immediately pour it off, otherwise retake 6.12 Drain each sample through a #400 sieve and rinse to remove pepsin-HCl - Sample must be drained into a metal hazardous liquid collector, subsequent rinses can go into the sin 6.13 Rinse the drained sample into a clean, labeled sample container using 70% ethanol, add enough ethanol to bring volume up to 100ml UCID ABOWASH DATE Animal ID ETOH (70%) 1/2 6.14 6.15 6.16 6.17 Add a waterproof label (as above) and close - Seal with parafilm if being stored before examination All excess pepsin-HCl solution and digestion should be disposed of in the hazardous liquid disposal - Record amount on disposal record The tray, beakers and tools should be washed as per lab protocols. The lab bench should be wiped down and disinfected. Sieve should be washed in the sonicator when procedure is complete 7.Equipment or Materials Required Materials 7.1 Small plastic tray 7.2 1.5L Erlenmeyer flask or 2L Beaker 7.3 Parafilm 7.4 Shaking Incubator 7.5 Blunt metal depressor or dull knife 7.6 500mL Erlenmeyer flask 7.7 #400 Sieve 7.8 Specimen Cups (3) 7.9 Waterproof paper 7.10 Grease marker or pencil 7.11 Metal hazardous liquid collector Materials 7.12 Pepsin – Should be kept refrigerated once opened 7.13 Ultrapure NaCl 7.14 HCl– Should be kept in Acid storage 7.15 70% Ethanol 8.Highlights / Critical Control Points 8.1 Concentration of pepsin-HCl solution should not be modified, nor should temperature of incubator increased beyond 39°C 9.Reporting – To be recorded in a blue lab book 9.1 Sample notes (i.e. Date, UCID, AID, Abo. Weight, Processing Date) should all be recorded before starting procedure 9.2 All times should be recorded in book - First incubation start ____; Removed at _____ - Second incubation start _____; Removed at _____ 9.3 Volume of final dilution and aliquots - e.g. 1.5L ; 150mL 10.Regulatory / Standards N/A 11.Trouble Shooting 11.1 Incubation length for the second incubation can be increased if large pieces of abomasum are still present in digest, should always be checked at 2hr 12.References Procedure Title: Method for the quantification and isolation of larval nematodes from abomasal digestions Minimum Review Requirements: Yearly Creation Date: 30 May 2011 Date of Next Review: 30 June 2011 Administrator of Procedure: Supervisor of Procedure: Authorized by: Table of Contents Title Page and Table of Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Version History .................................................................................................. 8 Introduction ........................................................................................................ 1 Definition ............................................................................................................ 8 Personnel ............................................................................................................ 8 Safety................................................................................................................... 8 Procedure ............................................................................................................ 3 Equipment or Materials Required ................................................................... 10 Highlights / Critical Control Points ................................................................ 10 Reporting .......................................................................................................... 10 Regulatory / Standards .................................................................................... 10 Trouble Shooting .............................................................................................. 10 References ........................................................................................................ 10 6. Version History Version #: Supersedes: 1.1 n/a The signatures below indicate the person(s) responsible to administer and supervise this procedure have read and agree toabide by the SOP attached Date Handwritten amendments to the official procedures can be made by a single line through the text, along with the date, and initialed by the authorized individual making the correction. Changes are to be noted below. Formal changes to this SOP are made on the date of revision or sooner, where required. Section Changes made to official copy Date Initials 7. Introduction This technique is used to analyse abomasal digest samples in order to quantify and isolate larval nematodes. 8. Definition N/A 9. Personnel SOP issued under authority of: Persons authorized to perform The SOP: Dr. S. Kutz, Jian Wang All lab staff 10. Safety As all materials are preserved in 70% ethanol the pathogenicity of the sample is vastly reduced, however standard laboratory safety procedures should still be followed. - Standard PPE (Lab coat and gloves) should be worn at all times - Wash hands and forearms after performing the analysis 6. Procedure 6.1 Take the sample to be examined and drain it through a #400 standard sieve 6.2 6.3 6.4 6.5 6.6 6.7 6.8 - Ethanol can be drained into the sink directly With water, rinse the sample container and label into the sieve and then rinse the sample repeatedly to remove any traces of ethanol Rinse the contents back into the sample container with water and fill to ~100mL Taking a 3mL bulb pipette with the tip cut off aliquot a small portion of the rinsed sample onto a grid petri dish, add water to dilute and examine on a dissecting microscope at 3.2. Count larva, using a desk counter, and remove them into a small cryotube filled halfway with 70% ethanol using a 10μL pipette - Once having ejected a larva into the cryotube dip the pipette tip into water so as to not agitate the next larva by adding ETOH to the petri-dish Once full dish has been examined, rinse into a large plastic beaker and repe When full sample has been examined place a freezer proof label on the cryotube and place into -80°C freezer for storage Discard waste down the laboratory sink UCID ABO. DIGEST (sample #) LARVA x (# in tube) AID ETOH DATE 7.Equipment or Materials Required Materials 7.1 #400 standard sieve 7.2 Grid petri-dish 7.3 3mL bulb-pipette with the tip cut-off 7.4 Cryotube 7.5 10μL pipette and tips 7.6 Large plastic beaker for waste 7.7 Dissecting microscope 7.8 Water squirt bottle Reagents 7.9 70% ethanol 8.Highlights / Critical Control Points N/A 9.Reporting – To be recorded in a blue lab book 9.1 Sample notes (i.e. Date, UCID, AID, Sample type (i.e. Abo. Digest) and Sample Number) should all be recorded before starting procedure 9.2 Concerns regarding wash procedure - If no concerns; Sample washed as per SOP: No Concerns 9.3 Number of larva accounted for (and reserved if different) 10.Regulatory / Standards N/A 11.Trouble Shooting N/A Appendix ll Variable | Obs Mean Std. Dev. Min Max -------------+------------------------------------------------------------Herd | 41 2 0 2 2 Age | 41 5.947561 2.517984 2.85 11.85 -------------+------------------------------------------------------------Pregnancy status | 41 .6829268 .471117 0 1 Lactation status | 41 .195122 .4012177 0 1 Body Weight | 41 56.47561 7.676222 38 69.5 -------------+------------------------------------------------------------Backfat depth | 41 6.02439 7.164104 0 25 -------------+------------------------------------------------------------Riney index | 41 54.13171 25.83972 18 136.5 -------------+------------------------------------------------------------Marrow fat% | 41 85.7122 3.708247 74.1 90.8 -------------+------------------------------------------------------------# Larvae | 18 637.2222 410.2339 265 2000 # Males | 18 33.33333 23.94847 5 85 # Females | 18 50.27778 35.82934 5 110 # Bits | 15 21.66667 16.10974 5 50 -------------+-------------------------------------------------------------