Mastigoproctus floridanus
Identity confidence: provisional. This is a genus, group, or trade name rather than a confirmed species. Treat it as the closest match we can stand behind, and use the more conservative end of any range.
Florida Giant Vinegaroon: Advanced Care Guide
Keeper Snapshot: Florida's own vinegaroon, and genuinely its own species since 2018 - not the desert giant most care sheets are written about. That matters twice over: Florida animals are SMALLER (measured Florida adults average about 45 mm, roughly 1.8 in, where hobby 'giant vinegaroon' figures come from Texas and Arizona animals), and they come from humid subtropical sand-scrub rather than desert, so the famous desert water-relations numbers do not transfer. Give it deep, well-drained sandy substrate it can actually dig, a flat piece of cork or bark on top because Florida records find these animals under surface debris as often as in burrows, a full water dish, and moisture low in the column with a dry surface. No venom, no bite worth the name - but it sprays concentrated acetic acid accurately for about a foot, and that is an eyes-and-nose problem, not a skin one. Watch it, do not carry it. Keep it spicy. - Big Z
Group: Spiders & Other InvertsDifficulty: Spice 2: BeginnerSetup: Subtropical sand-scrub burrower with surface refugiaHandling: Handling discouraged. No venom and no real bite, but the acetic acid spray is genuinely dangerous to eyes, and the whip-like flagellum breaks easily. Catch cup for transfers.
Use This Guide Safely
- Confirm the exact animal. Match this guide to the species, locality, size, and life stage on your label. If the ID is uncertain, use the more conservative part of the range and ask before changing the setup.
- Change one thing at a time. Treat temperature and humidity as target zones, then watch posture, burrowing, drinking, feeding, and molt behavior before making another adjustment.
- Respect the handling boundary. If the guide says no handling, fast, defensive, or medically significant, plan transfers with catch cups, locked lids, and no bare hands. For serious bites, stings, or symptoms, seek emergency medical care.
Quick Snapshot
| Temperature | Ordinary room warmth, roughly 72-82F, with a normal indoor night drop. No heat mat, no hot spot. LABELLED SCOPE - HOUSE STANDARD, NOT SPECIES EVIDENCE: no temperature study exists for this species and every hobby figure in circulation was refuted or narrowed during verification. The nearest measured work is on Chihuahuan Desert congeners from Big Bend, Texas, which settled at 23-28.9C on a gradient, and the 2018 revision explicitly warns that this desert research does not describe the more mesic Florida animal. Depth is your real temperature control: in a measured congeneric population the soil surface swung between 59.5C and -15C while the 15-30 cm layer stayed within 3.2-38.1C. |
|---|---|
| Humidity | No numeric % ambient target - manage by substrate, not by air. Keep the bottom third of the column lightly damp, let the top inch dry, and keep a shallow pebble-packed water dish full at all times. LABELLED SCOPE: no humidity figure has ever been published for this species; congeneric embryo work failed entirely at 12% RH and succeeded at 40% and 75%, and dry air measurably lowers heat tolerance in the genus, which is why the damp lower layer and the dish matter more than any wall gauge. |
| Setup Type | Subtropical sand-scrub burrower with surface refugia |
| Substrate | 6 in or more of packable sandy soil - sand cut with topsoil, coco fiber or clay loam. Coco fiber alone collapses and will not hold a burrow or a molt chamber. LABELLED SCOPE: the depth figure is Big Z's house standard, not a published requirement. The only peer-reviewed substrate figure for the genus is a laboratory colony jar filled to 16 cm with moistened sandy loam, for the Arizona species. |
| Feeding | Soft-bodied insects - roaches, crickets, termites - fed to body condition rather than to a schedule |
| Care Difficulty | Spice 2: Beginner |
| Handling | Handling discouraged. No venom and no real bite, but the acetic acid spray is genuinely dangerous to eyes, and the whip-like flagellum breaks easily. Catch cup for transfers. |
Humidity zones: Very Low under 30% - Low 30-60% - Low-Moderate 40-70% - Moderate 60-80% - Moderate-High 70-85% - High 80%+ - Very High 90%+
Enclosure Format / Size Class
- Measured Florida adults: 10 females averaged 45.3 mm total length (range 38.0-50.0 mm) and one Florida male measured 45.0 mm - Muma 1967, Florida State Collection of Arthropods. Telsons were mostly broken, so these are body measurements.
- The 2018 revision's type material gives maxima of 51.8 mm for males and 60.6 mm for females, measured from the anterior margin of the carapace to the posterior margin of the pygidium, excluding the flagellum. The two sources measure differently and disagree at the top end; both are quoted rather than averaged.
- Florida animals are explicitly recorded as SMALLER than giant vinegaroons elsewhere in the old lumped range, with the sexes more nearly equal in size.
- Do not size an enclosure from hobby 'giant vinegaroon' figures. Those describe Texas and Arizona animals - Texas A&M quotes 1.5-3 in, which runs well above every measured Florida figure.
- NO juvenile or sub-adult size data exists for this species. Size the enclosure from the animal in front of you.
Warnings First
- NO VENOM. This is the one safety statement here that rests on agreed, order-level biology: Thelyphonida have no venom glands. UF/IFAS Extension states the animal has neither a venom-filled sting nor a venomous bite.
- THE SPRAY IS THE REAL RISK AND IT IS AN EYES-AND-AIRWAY RISK. The pygidial discharge is an aimed acidic spray. Treat any contact with eyes, nose or mouth as the serious case: flush with clean water and seek medical advice for anything beyond brief irritation. Do not put your face over an open enclosure.
- DO NOT ASSUME IT IS HARMLESS ON SKIN. Extension material describes the spray as not dangerous to skin, but Muma's first-hand Florida account reports mild burning of the skin, smarting eyes and choking nausea lasting several minutes. Where a primary account and an uncited summary disagree, this guide takes the more cautious one.
- SOURCES DISAGREE ON RANGE. UF/IFAS gives a few inches to about a foot; Muma records being sprayed in the face from 18 inches to two feet. Assume the longer figure and keep your distance accordingly.
- NO CHEMISTRY IS PUBLISHED FOR THIS SPECIES. The well-known acetic-acid analysis was performed on the desert species M. tohono, and the 2018 revision states plainly that nothing is known about the secretions of other species in the complex. Any percentage you see quoted for a Florida vinegaroon is borrowed from a different animal, so none is given here.
- IT DOES NOT TRULY BITE, but a mishandled pedipalp pinch can break skin, and Muma flags secondary infection as the real consequence rather than any toxin.
- THE FLAGELLUM IS FRAGILE. In a wild congeneric sample, 11% of 609 animals had partial or total tail loss. It regrows to about half length after a molt and the animal can still aim without it - but never grab or lift by it.
- SOLITARY HOUSING once the young leave the mother's back. Cannibalism of small instars by large animals is documented in the genus.
- LONG SEALED-IN PERIODS ARE NORMAL AND ARE NOT AN EMERGENCY. Keeper reports for this genus run from about 7 months to nearly 2 years, and that is when molting and egg-laying happen. Do not excavate. LABELLED SCOPE: those reports are from southwestern animals; Florida behaviour has not been studied and may differ.
- DO NOT RELEASE IT, EVER, ANYWHERE. Florida Statute 581.083 prohibits introducing or releasing any arthropod in Florida without a special permit from the Department of Agriculture and Consumer Services.
Simple Care
- Deep sandy substrate it can dig - 6 in or more, packable, not pure coco fiber.
- Lay a flat cork or bark piece on the surface. Florida records find these animals under logs and debris at least as often as in burrows.
- Damp lower third, dry surface. Add water to one area of the substrate, not over the animal.
- Shallow water dish packed with pebbles, full at all times, so nymphs cannot drown.
- Normal room warmth. No heat mat, no hot spot.
- Feed soft-bodied insects every 4-7 days and pull uneaten prey within a day.
- House singly once the young leave the mother.
- Work over a bin, keep your face out of the enclosure, and use a catch cup rather than hands.
Advanced Keeper Notes
Enclosure & Microclimate
- This species comes from Florida scrub and scrubby flatwoods - deep, nutrient-poor, well-drained acidic sands with bare sand openings. That is the substrate to reproduce: sandy and packable, drained, not a peaty tropical mix.
- Give both options, because the published record is genuinely split. UF/IFAS describes daytime concealment in burrows dug with the pedipalps in deep well-drained sandy soils; the 2018 revision's only microhabitat records for M. floridanus are surface cover - rotten logs, debris, and houses - and Muma's Florida survey says the same. Deep diggable substrate AND a flat surface refuge covers both behaviours.
- Depth is temperature and moisture management, not decoration. In a measured congeneric population the soil surface hit 59.5C and -15C across the year while the 15-30 cm depths where the animals sit never went above 38.1C nor below 3.2C. Depth is how the animal escapes conditions you got wrong.
- Run the moisture as a vertical gradient and read it by hand: bottom third holds shape when squeezed and releases no free water, middle cool and damp, top inch dry. That gradient is the choice you are offering.
- Congeneric burrows run to roughly 30 cm deep and end in a chamber the animal occupies by day, in sandy loam. You will not fit 30 cm in a starter enclosure and do not need to - but the deeper and more packable the column, the better this animal settles.
- A published laboratory setup for the genus used a 4-litre jar 15 cm across by 24 cm high, filled to 16 cm with moistened sandy-loam soil from the collection site, with a screened lid giving limited ventilation.
- Nocturnal with strong negative phototaxis. Keep it out of bright light and expect to see it after dark.
Feeding, Growth & Maintenance
- Diet is the best-supported husbandry fact here. UF/IFAS names the Florida woods roach Eurycotis floridana as common natural prey of Florida adults, within a base of soft-bodied insects - termites, cockroaches, crickets - killed by crushing between the pedipalp teeth. Recorded diet also includes arachnids and amphibians, and Florida field work adds millipedes.
- It is not deterred by chemically defended prey. Florida whip scorpions attack, kill and eat the benzoquinone-defended scrub millipede Floridobolus penneri without being put off. Prey handling is a pedipalp grasp, then a bite through an intersegmental membrane, then liquid feeding - observed animals were ingesting within 15-30 minutes and left only the millipede's rings.
- FEED TO CONDITION, NOT TO A CALENDAR. No feeding schedule for this species has ever been published. The hobby spread runs from weekly to every three or four weeks, and verification found the two apparently independent sources are the same author writing on two commercially linked pages. The one laboratory figure - twice weekly - covers protonymphs and deutonymphs of a desert congener only. Judge the abdomen, and pull uneaten prey within a day so nothing chews a soft, freshly molted animal.
- GROWTH AND LIFESPAN ARE NOT ESTABLISHED FOR THIS SPECIES, and this guide deliberately publishes no number. As of 2024 only two thelyphonid species worldwide had published life span and fecundity data, and this is not one of them; the figures in circulation range from 3 to 20 years across six sources, none of them citing anything retrievable. The Florida life-history paper that probably underlies all of them - Weygoldt 1971, written about Florida animals - could not be retrieved this pass. Expect a slow-growing, long-lived animal and leave it at that.
- A sealed-in, non-feeding animal is normal. It stops eating going into the buried period and resumes on emergence.
Possible Origin / Range
- Likely native range: Endemic to Florida - the 2018 revision states it is known only from the state of Florida. Verified county records include Alachua, Brevard, Highlands, Hillsborough, Lake, Lee, Levy, Manatee, Marion, Martin, Orange, Polk, Sarasota and St. Johns, spanning the peninsula and the southern keys. Habitat is subtropical scrub forest at roughly 10-100 m elevation; direct field observation places it in scrubby flatwoods on sandy soil at 40-43 m in Highlands County. Surface activity in Florida runs with the rainy season, roughly May or June to November, with the driest part of the year spent underground.
- Habitat translation: Deep well-drained Florida sand with a flat surface refuge, moisture held low in the column rather than in the air, permanent drinking water, ordinary room warmth, and darkness. Not a desert setup and not a wet tropical one.
Advanced Keeper Details
- TAXONOMY, AND WHY THIS GUIDE EXISTS SEPARATELY. Barrales-Alcala, Francke & Prendini (2018, Bull. Am. Mus. Nat. Hist. 418) revalidated Mastigoproctus floridanus (Lonnberg, 1897) from synonymy with M. giganteus, on adult-male morphology, raising North American Thelyphonida from one species to seven. Originally described as the subspecies M. giganteus floridanus and synonymised by Kraepelin in 1899, Florida material was carried under the name M. giganteus for over a century - which is why almost every source about this animal is filed under the wrong name.
- THE BACKBONES DISAGREE, WHICH IS WHY IDENTITY CONFIDENCE IS PROVISIONAL. GBIF (usageKey 6895049), ITIS (TSN 1123448, 'TWG standards met'), NatureServe and iNaturalist all accept M. floridanus. ITIS has ingested the whole post-2018 arrangement. The World Arachnid Catalog - the specialist world catalogue for this order - still lists floridanus among synonyms on its M. giganteus record, citing the 2018 revision on the same page without acting on it, and has no floridanus record at all. Until the order's own catalogue moves, this is the closest identity Big Z's can stand behind rather than a settled one.
- DO NOT IMPORT DESERT HUSBANDRY. The revision states that the well-known water-relations research published on 'M. giganteus' was carried out on M. tohono, a desert species, and expressly calls for study of water retention in more mesic species such as M. floridanus. That is a published statement that no water-relations data for this animal exists. Deep-burrow aestivation and hibernation in that literature likewise belong to the Arizona/Sonora animal.
- WHAT IS MISSING, STATED PLAINLY. There is no zoo, aquarium or veterinary husbandry source for this genus anywhere in the corpus searched - the AAZK terrestrial invertebrate manual was read in full and contains no mention of vinegaroons. No care sheet exists under the name M. floridanus. The only quantitative burrow-architecture study for the genus could not be retrieved, and neither could the Florida life-history and Florida sandhill-seasonality papers. Every enclosure set-point in this guide is therefore house standard or labelled congeneric, not professional captive-care authority.
- HOBBY NUMBERS ARE COPY-SPREAD. The temperature and humidity figures dominating vinegaroon care sheets propagate by verbatim copying between commercially linked pages rather than by independent observation. They are recorded as the hobby spread and are not this guide's basis.
- LEGAL, AND WHAT IS UNRESOLVED. NatureServe records the species as native, endemic to Florida, GNR/NNR. Florida FWC's Captive Wildlife Office does not regulate arachnids. Florida Statute 581.083 governs introduction and release of arthropods within Florida, and FDACS permits arthropod movement into the state. NOT VERIFIED THIS PASS: federal ESA listing could not be checked against the USFWS database, and CITES status could not be retrieved from any official route. Buyers should check their own state's rules before purchase; this guide asserts none.
- Sources: the full Big Z APA 7 reference list lives at References.