The Lionfish InvasionFlorida Fish and Wildlife Conservation Commission

Division of Marine Fisheries Management

What is an Invasive Species?▪ Animals, plants, or other organisms introduced by people in

places outside of their natural habitat that cause negative

impacts on humans and/or the native ecosystem.

▪ Rapidly reproduce and become established in new habitat

▪ Cause negative impacts like preying on native species,

physical damage to habitat, introduction of diseases, and

competition for resources

Marine Invasions

▪ 37 nonnative marine fishes in Florida, but

have not become established▪ USGS non-indigenous aquatic species database 2017

▪ Lionfish are a marine fish that has

become successfully established in

nonnative range and classified as

the worst marine invasion to date

Lionfish

(Pterois volitans & P. miles)

▪ Tropical predatory fish from Indo-Pacific region

▪ Introduced by an aquarium release in 1980’s

▪ Established in western Atlantic Ocean,

Caribbean Sea, and Gulf of Mexico

▪ Density and biomass exceed that in

their native range

Invasive Characteristics▪ Wide range of habitat use – natural and artificial, 1 – 1,000 ft.

depths, tolerate temperatures as low as 50°F

▪ Sexually mature at 1 year; spawn frequently (every 4 days); up to

30,000 eggs/spawn

▪ Consume economically & ecologically-important species; over 90

different species found in stomach; swallow prey over half body size

▪ 18 venomous spines; neuromuscular toxin; treatment: apply heat

▪ Unique coloration – native predators do not recognize as prey

▪ Economically important species

▪ Fish: groupers, snappers, baitfish

▪ Invertebrates: shrimp, crabs, lobster

Lionfish Diet

▪ Ecologically important species

▪ Cleaners: maintain health of reef fish by consuming parasites

▪ Grazers: maintain health of coral reefs by consuming algae

Lionfish Diet

Effects on Native Ecosystems

▪ Consume over 90 different species of

native fish and invertebrate species

▪ Recent documentation of lionfish

consumption of undescribed mesophotic goby (Tornabene & Baldwin 2017)

▪ Reduction in recruitment and prey

biomass:

▪ 79% reduction in juvenile fish recruitment to

new reefs observed in the Bahamas (Albins & Hixon 2008)

▪ 2.6 times reduction in recruitment compared

to a native predator (Albins 2013)

▪ 65% reduction in prey biomass (Green et al. 2012)

▪ Non-consumptive effects: Competition

for resources with other top and

mesopredators (Raymond et al. 2014)

▪ Habitat degradation

▪ Phase shift to algal-dominated reefs (Lesser

& Slattery 2011)

▪ Absence of natural, consistent control

mechanism

▪ Humans as a predator: Models

estimate 27-65% adult populations

removed monthly to achieve

substantial declines (Morris et al. 2010)

Effects on Native Ecosystems

Lionfish Landings by Gear Type

0

20000

40000

60000

80000

100000

120000

140000

2010 2011 2012 2013 2014 2015 2016 2017

Nu

mb

er

of

lio

nfi

sh

(lb

s)

Year

Trawl

Traps

Hook and

LineDiving

Conflict Wildlife – Lionfish • Agency strategic goals: Minimize human health and safety, environmental,

social, economic, and other adverse impacts

▪ Encourage removal efforts & increase

recreational and commercial harvest tracking

• Remove regulatory barriers to harvest

• Support lionfish tournaments

• Promote incentive removal programs

• Support innovative strategies for removal

▪ Increase public awareness

• Traveling “Be the Predator” outreach booth

• Workshops and school dissections

• Lionfish Removal and Awareness Day

▪ Promote consumption and commercial market

From 2014-2018 FWC has tracked the removal of over

539,300 lionfish from Florida waters!

Questions?Video and Diver: Meaghan Faletti

Goals of Dissection

▪ Provide unique information on the physiology,

biology and ecology

▪ Population structure

▪ Age and growth

▪ Reproductive biology

▪ Food web ecology

Venomous Spines

• 18 venomous spines

• 13 on dorsal fin

• 1 on each pelvic fin

• 3 on anal fin

• Spine contains grooves (not hollow) that house venomous

glandular tissue

External Anatomy

Key:

A - Dorsal spines*

B - Soft Dorsal

C - Caudal Fin

D - Pectoral Fin

E - Pelvic Fin*

F - Anal Fin*

G - Super-ocular

tentacles

H - Opercular spines

* - Contain venom

Photo credit C. Calloway; Green et al. 2012

*

*

*

External measurements

Weight

▪ Application: growth, body

condition, population size

structure

▪ Methods:

▪ Blot fish dry of excess water with a

paper towel

▪ Place weigh boat or specimen tray

on the scale and tare it

▪ Place fish into weigh boat or tray –

ensure not resting on table

▪ Record measurement in grams.

External measurementsTotal length

▪ Application: Growth, body

condition, population size

structure

▪ Methods:

▪ Place the lionfish on top of the

measuring tape

▪ The tape should run parallel to the

fish’s midline from snout to tail

▪ Measure from the tip of the snout

to the longest point on the tail

▪ Ensure mouth is closed

▪ Record measurement to the

nearest 1 mm

External measurements

Mouth gape

▪ Application: Feeding ecology

▪ Methods:

▪ Open the mouth to the fullest extent (without overextending)

▪ Using a ruler, measure to the nearest 1 mm

Gape height Gape width

Opening the Gut Cavity

A. Incision from urogenital

opening towards the base of

the pelvic fins (pelvic girdle).

B. Deeper cut will be required

to sever the pelvic girdle.

C. Cut along the rear edge of

the gill arch toward the

dorsal fin.

D. Lift the flank to expose the

gut cavity and internal

organs. Cut through any

minor connecting tissue as

needed.Green et al. 2012

Internal Anatomy

Key:A. Gill rakers and filaments

B. Swim bladder

C. Swim bladder muscles

D. Liver

E. Gonad

F. Urinary bladder

G. Interstitial fatty deposits

H. Stomach

I. Intestine

Green et al. 2012

Reproductive Organs

Immature gonadsMale testes

Female ovary

▪ Application: Reproductive physiology

▪ Methods: ▪ Remove both gonads

▪ Place in weigh boat on scale

▪ Record measurement in grams (g)

Green et al. 2012

Opening the StomachApplication: Feeding ecology

A. Sever the esophagus where it

terminates.

B. Insert scissors into the

esophageal opening of the

stomach.

C. Make a shallow cut along the

length of the stomach wall to

the intestine opening.

D. Invert the stomach and

remove all prey items; place

prey onto a clean surface for

identification. Green et al. 2012

Prey Score Digestion LevelScore Description Identification resolution

1

No degradation or digestion;

prey item appears freshly

consumed

Species

2Minor degradation to fin rays

and scale pigmentationSpecies

3

Substantial degradation to

external structures such as fin

rays and scale pigmentation

Family

4

Major degradation: parts of

body flesh missing, no

pigmentation, length

measurement not possible

Vertebrate/invertebrate

5

Prey item fully digested and

reduced to mush-like

condition

Visual identification not

possible

Green et al. 2012

Interstitial Fat Deposits

(optional)• Remove fat deposits from gut cavity

• Fill graduated cylinder to 50 mL

• Measure volume after adding fat deposits to

the graduated cylinder