Leopard Slug
Limax maximus Linnaeus, 1758
Leopard Slug in all of Ohio- Kingdom
- Animalia
- Phylum
- Mollusca
- Class
- Gastropoda
- Family
- Limacidae
- Genus
- Limax
Introduced and invasive status
Introduced in Ohio: iNaturalist (opens in a new tab)
Also listed
- Introduced and assessed as invasive in the lower 48 states
iNaturalist's volunteer curators list it as introduced in their Ohio checklist.
US-RIIS assesses a species as invasive when it causes, or is likely to cause, harm there, or is at least locally abundant and harmful ecologically, economically, or to health.
Status: Simpson A, Sellers E, Pagad S (2023). United States Register of Introduced and Invasive Species (US-RIIS), ver. 2.0. U.S. Geological Survey, https://doi.org/10.5066/P9KFFTOD (opens in a new tab)
Range
Where it is recorded
Season shown in 1 of Ohio's 88 counties. Explore Ohio
- No result yet (30)
- Recorded, too few records for a result (55)
- Recorded, season not shown (2)
- Season shown (1)
Counties as a table
| County | Records |
|---|---|
| Adams County | No qualifying records yet |
| Allen County | Recorded, too few records for a result |
| Ashland County | No qualifying records yet |
| Ashtabula County | Recorded, too few records for a result |
| Athens County | 24 · Recorded, season not shown |
| Auglaize County | No qualifying records yet |
| Belmont County | Recorded, too few records for a result |
| Brown County | Recorded, too few records for a result |
| Butler County | Recorded, too few records for a result |
| Carroll County | No qualifying records yet |
| Champaign County | Recorded, too few records for a result |
| Clark County | Recorded, too few records for a result |
| Clermont County | Recorded, too few records for a result |
| Clinton County | Recorded, too few records for a result |
| Columbiana County | No qualifying records yet |
| Coshocton County | No qualifying records yet |
| Crawford County | Recorded, too few records for a result |
| Cuyahoga County | 68 · Season shown |
| Darke County | Recorded, too few records for a result |
| Defiance County | No qualifying records yet |
| Delaware County | No qualifying records yet |
| Erie County | Recorded, too few records for a result |
| Fairfield County | Recorded, too few records for a result |
| Fayette County | Recorded, too few records for a result |
| Franklin County | 35 · Recorded, season not shown |
| Fulton County | No qualifying records yet |
| Gallia County | Recorded, too few records for a result |
| Geauga County | Recorded, too few records for a result |
| Greene County | Recorded, too few records for a result |
| Guernsey County | Recorded, too few records for a result |
| Hamilton County | Recorded, too few records for a result |
| Hancock County | Recorded, too few records for a result |
| Hardin County | Recorded, too few records for a result |
| Harrison County | No qualifying records yet |
| Henry County | Recorded, too few records for a result |
| Highland County | Recorded, too few records for a result |
| Hocking County | No qualifying records yet |
| Holmes County | No qualifying records yet |
| Huron County | No qualifying records yet |
| Jackson County | Recorded, too few records for a result |
| Jefferson County | Recorded, too few records for a result |
| Knox County | Recorded, too few records for a result |
| Lake County | Recorded, too few records for a result |
| Lawrence County | Recorded, too few records for a result |
| Licking County | Recorded, too few records for a result |
| Logan County | Recorded, too few records for a result |
| Lorain County | Recorded, too few records for a result |
| Lucas County | Recorded, too few records for a result |
| Madison County | Recorded, too few records for a result |
| Mahoning County | Recorded, too few records for a result |
| Marion County | Recorded, too few records for a result |
| Medina County | Recorded, too few records for a result |
| Meigs County | Recorded, too few records for a result |
| Mercer County | No qualifying records yet |
| Miami County | Recorded, too few records for a result |
| Monroe County | No qualifying records yet |
| Montgomery County | Recorded, too few records for a result |
| Morgan County | No qualifying records yet |
| Morrow County | No qualifying records yet |
| Muskingum County | No qualifying records yet |
| Noble County | No qualifying records yet |
| Ottawa County | Recorded, too few records for a result |
| Paulding County | Recorded, too few records for a result |
| Perry County | No qualifying records yet |
| Pickaway County | No qualifying records yet |
| Pike County | Recorded, too few records for a result |
| Portage County | No qualifying records yet |
| Preble County | No qualifying records yet |
| Putnam County | Recorded, too few records for a result |
| Richland County | Recorded, too few records for a result |
| Ross County | Recorded, too few records for a result |
| Sandusky County | Recorded, too few records for a result |
| Scioto County | Recorded, too few records for a result |
| Seneca County | No qualifying records yet |
| Shelby County | No qualifying records yet |
| Stark County | Recorded, too few records for a result |
| Summit County | Recorded, too few records for a result |
| Trumbull County | No qualifying records yet |
| Tuscarawas County | No qualifying records yet |
| Union County | Recorded, too few records for a result |
| Van Wert County | Recorded, too few records for a result |
| Vinton County | No qualifying records yet |
| Warren County | Recorded, too few records for a result |
| Washington County | Recorded, too few records for a result |
| Wayne County | Recorded, too few records for a result |
| Williams County | No qualifying records yet |
| Wood County | Recorded, too few records for a result |
| Wyandot County | No qualifying records yet |
No mapped range from the range source used, the USGS Gap Analysis Project, which maps land vertebrates only.
Season
When it is recorded
In Athens County
Not enough evidence
Records per week from 24 records in 9 of the 10 years from 2016 to 2025. Shows when people recorded it, not a season or how common it is.
Show as a table
| Week | Records of Leopard Slug | Years recorded | Records of all species |
|---|---|---|---|
| Jan 4–10 | 0 | 0 | 74 |
| Jan 11–17 | 0 | 0 | 132 |
| Jan 18–24 | 0 | 0 | 107 |
| Jan 25–31 | 0 | 0 | 219 |
| Feb 1–7 | 0 | 0 | 392 |
| Feb 8–14 | 0 | 0 | 232 |
| Feb 15–21 | 0 | 0 | 235 |
| Feb 22–28 | 0 | 0 | 361 |
| Mar 1–7 | 0 | 0 | 532 |
| Mar 8–14 | 0 | 0 | 466 |
| Mar 15–21 | 0 | 0 | 593 |
| Mar 22–28 | 1 | 1 | 950 |
| Mar 29 – Apr 4 | 0 | 0 | 1,265 |
| Apr 5–11 | 0 | 0 | 1,616 |
| Apr 12–18 | 0 | 0 | 1,804 |
| Apr 19–25 | 1 | 1 | 1,926 |
| Apr 26 – May 2 | 1 | 1 | 2,291 |
| May 3–9 | 0 | 0 | 1,407 |
| May 10–16 | 0 | 0 | 1,408 |
| May 17–23 | 0 | 0 | 2,542 |
| May 24–30 | 1 | 1 | 1,821 |
| May 31 – Jun 6 | 1 | 1 | 798 |
| Jun 7–13 | 1 | 1 | 775 |
| Jun 14–20 | 1 | 1 | 830 |
| Jun 21–27 | 1 | 1 | 700 |
| Jun 28 – Jul 4 | 3 | 1 | 549 |
| Jul 5–11 | 0 | 0 | 664 |
| Jul 12–18 | 1 | 1 | 869 |
| Jul 19–25 | 2 | 1 | 700 |
| Jul 26 – Aug 1 | 1 | 1 | 673 |
| Aug 2–8 | 1 | 1 | 613 |
| Aug 9–15 | 0 | 0 | 871 |
| Aug 16–22 | 1 | 1 | 807 |
| Aug 23–29 | 2 | 2 | 1,289 |
| Aug 30 – Sep 5 | 1 | 1 | 2,925 |
| Sep 6–12 | 1 | 1 | 2,530 |
| Sep 13–19 | 1 | 1 | 2,417 |
| Sep 20–26 | 0 | 0 | 1,530 |
| Sep 27 – Oct 3 | 0 | 0 | 1,628 |
| Oct 4–10 | 0 | 0 | 1,836 |
| Oct 11–17 | 0 | 0 | 1,920 |
| Oct 18–24 | 0 | 0 | 825 |
| Oct 25–31 | 0 | 0 | 930 |
| Nov 1–7 | 0 | 0 | 881 |
| Nov 8–14 | 1 | 1 | 846 |
| Nov 15–21 | 0 | 0 | 573 |
| Nov 22–28 | 1 | 1 | 536 |
| Nov 29 – Dec 5 | 0 | 0 | 270 |
| Dec 6–12 | 0 | 0 | 982 |
| Dec 13–19 | 0 | 0 | 158 |
| Dec 20–26 | 0 | 0 | 106 |
| Dec 27 – Jan 2 | 0 | 0 | 95 |
In Ohio
Late April to late October, middle week Jul 26 – Aug 1
Records per week from 450 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not how common it is. The grey bars show how many records of all species were made here each week, so you can see when recording itself was high or low; the season is not adjusted by them.
Recorded on 352 dates. Latest record: December 2025.
Show as a table
| Week | Records of Leopard Slug | Years recorded | Records of all species |
|---|---|---|---|
| Jan 4–10 | 0 | 0 | 6,211 |
| Jan 11–17 | 0 | 0 | 5,146 |
| Jan 18–24 | 0 | 0 | 4,645 |
| Jan 25–31 | 0 | 0 | 4,698 |
| Feb 1–7 | 0 | 0 | 6,023 |
| Feb 8–14 | 0 | 0 | 5,888 |
| Feb 15–21 | 0 | 0 | 5,436 |
| Feb 22–28 | 0 | 0 | 6,846 |
| Mar 1–7 | 3 | 3 | 8,321 |
| Mar 8–14 | 1 | 1 | 10,384 |
| Mar 15–21 | 1 | 1 | 12,620 |
| Mar 22–28 | 3 | 3 | 13,949 |
| Mar 29 – Apr 4 | 1 | 1 | 19,661 |
| Apr 5–11 | 4 | 2 | 26,860 |
| Apr 12–18 | 5 | 3 | 39,925 |
| Apr 19–25 | 4 | 3 | 41,623 |
| Apr 26 – May 2 | 9 | 5 | 56,391 |
| May 3–9 | 9 | 5 | 52,952 |
| May 10–16 | 11 | 5 | 53,785 |
| May 17–23 | 10 | 7 | 57,698 |
| May 24–30 | 16 | 7 | 54,651 |
| May 31 – Jun 6 | 22 | 7 | 53,099 |
| Jun 7–13 | 23 | 6 | 53,700 |
| Jun 14–20 | 15 | 4 | 56,625 |
| Jun 21–27 | 6 | 4 | 55,361 |
| Jun 28 – Jul 4 | 16 | 7 | 58,477 |
| Jul 5–11 | 14 | 5 | 61,336 |
| Jul 12–18 | 13 | 7 | 64,722 |
| Jul 19–25 | 24 | 5 | 69,753 |
| Jul 26 – Aug 1 | 16 | 8 | 59,416 |
| Aug 2–8 | 12 | 7 | 59,712 |
| Aug 9–15 | 12 | 5 | 55,994 |
| Aug 16–22 | 25 | 7 | 54,328 |
| Aug 23–29 | 16 | 6 | 51,772 |
| Aug 30 – Sep 5 | 27 | 8 | 57,167 |
| Sep 6–12 | 26 | 9 | 59,075 |
| Sep 13–19 | 22 | 6 | 54,543 |
| Sep 20–26 | 21 | 8 | 45,860 |
| Sep 27 – Oct 3 | 13 | 6 | 43,180 |
| Oct 4–10 | 11 | 4 | 37,841 |
| Oct 11–17 | 7 | 4 | 30,824 |
| Oct 18–24 | 5 | 4 | 21,156 |
| Oct 25–31 | 5 | 4 | 19,021 |
| Nov 1–7 | 7 | 3 | 14,172 |
| Nov 8–14 | 7 | 5 | 12,621 |
| Nov 15–21 | 1 | 1 | 7,965 |
| Nov 22–28 | 2 | 2 | 8,136 |
| Nov 29 – Dec 5 | 1 | 1 | 6,083 |
| Dec 6–12 | 0 | 0 | 6,004 |
| Dec 13–19 | 0 | 0 | 5,423 |
| Dec 20–26 | 2 | 1 | 5,661 |
| Dec 27 – Jan 2 | 2 | 2 | 8,459 |
What these results show
These results show when people recorded a species, not when or where it occurs. Missing weeks and low counts do not mean absence or scarcity, and counts are not abundance. Contributed records reflect where, when and what people chose to observe.
Identification
How to identify it
Often confused with
- Changeable Mantleslug Megapallifera mutabilisOften confused in Ohio: 22 identifications in Ohio named one where the other was meant
- Milky Slug Deroceras reticulatum122 identifications worldwide named one where the other was meant
- Carolina Mantleslug Philomycus carolinianus87 identifications worldwide named one where the other was meant
- Meadow Slug Deroceras laeve86 identifications worldwide named one where the other was meant
- Garden Arion Arion hortensis46 identifications worldwide named one where the other was meant
From iNaturalist’s similar-species counts, refreshed monthly: confusions in Ohio first, then worldwide. Only species with an Ohio result are listed.
Months not reported
- Jan: no record
- Feb: recorded
- Mar: recorded
- Apr: recorded
- May: recorded
- Jun: recorded
- Jul: recorded
- Aug: recorded
- Sep: recorded
- Oct: recorded
- Nov: recorded
- Dec: recorded
Not reported in Ohio in January, 2016 to 2025.
Time of day it is recorded
From 448 Ohio records with a time. Most records are made when people are outside, so night and early-morning species are under-recorded.
Land cover where it is recorded
| Land cover | Its recordsAll Ohio records |
|---|---|
| Developed | 90%49% |
| Forest | 6%31% |
| Farmland | 2%11% |
| Grassland and shrub | 2%0.9% |
| Open water | 0.4%3% |
From 251 records placed within 100 m, beside all Ohio records placed the same way. People record where they go, so this shows where records come from, not where the species lives. Land cover: USGS Annual NLCD, 2025 (opens in a new tab)
Sources
Where these results come from
- Records from iNaturalist research-grade observations and expert-identified GBIF datasets, CC0, CC BY and CC BY-NC. Sources
- Seasons use the published method and its evidence thresholds. Methods
- See it on iNaturalist (opens in a new tab)OpenPhenology is independent and not affiliated with iNaturalist.
Records behind the Ohio result
450 records from 2 datasets.
- iNaturalist Research-grade Observations (opens in a new tab) · iNaturalist.org · 448 recordsiNaturalist contributors, iNaturalist (2026). iNaturalist Research-grade Observations. iNaturalist.org. Occurrence dataset https://doi.org/10.15468/ab3s5x accessed via GBIF.org on 2026-11-13.
- iNaturalist observations (opens in a new tab) · iNaturalist.org · 2 recordsiNaturalist. Available from https://www.inaturalist.org. Accessed 2026-11-13
To cite: the GBIF download doi:10.15468/dl.y2jkt8 (opens in a new tab).
A spreadsheet (CSV) with a link to each record, on iNaturalist or GBIF. Records whose location was hidden by the observer or the source are counted but not linked.