Boa Constrictors and their Relatives – Natural History and Captive Care

Malagasy tree boaHello, Frank Indiviglio here.  The 53 species in the family Boidae are an amazingly diverse group of snakes that have colonized habitats ranging from rainforests to deserts, in countries as diverse as Canada and India. Among them we find treetop dwellers, aquatic species, confirmed burrowers and generalists equally at home in farmland, savannas, desert fringes and forests. I’ve had the good fortune of studying Anacondas, Rosy Boas and others in the wild, and remain fascinated by all.  Please be sure to post some thoughts about your favorites below.

Classification and Terminology

The family Boidae is divided into 3 subfamilies. Most boas are placed in the subfamily Boinae. The ten Sand Boas of southern Europe, Africa and Asia, the Calabar Ground “Python” and North America’s Rubber and Rosy Boas are classified in the subfamily Erycinae. Ungaliophiinae is comprised of the Oaxacan, Isthmian and Panamanian Dwarf Boas. 

The term “boa” usually refers to the Common Boa. A short “first name” is applied to others, i.e. Rough-Scaled Boa, Rainbow Boa, Malagasy Tree Boa, Pacific Boa.  Read More »

Water Scorpion Care and Habits – Aquatic Insects for Arachnid Fans

Water Scorpion with guppyHello, Frank Indiviglio here.  Over the past several months, I’ve spent much time collecting aquatic insects with my nephew, who is quite the intense little naturalist (please see photos – I’m having as much fun as he!).  In addition to our usual haul of backswimmers, predacious diving beetles, dragonfly larvae and the like, this season I was pleased to find a healthy population of Brown Water Scorpions (Ranatra fusca).  Combining characteristics of mantids, walking sticks and scorpions, all modified for life underwater, these amazing creatures are simple to keep and fascinating to get to know. 

Aquatic Insects as Pets

In years past, I set up aquatic insect exhibits for several zoos and public aquariums, but it seems that interest remains rather low among private invertebrate keepers.  This surprises me, as their range of lifestyles rivals that of their land-bound cousins, and never fails to astonish me even after all these years.  Please see this article for information on aquatic beetle care, and watch for others in the future. 

Natural History 


Water Scorpions are classified in the order Hemiptera and the family Nepidae.  Members of the order Hemiptera, known as True Bugs, have sucking, beak-like mouthparts.  Examples include cicadas, giant water bugs, backswimmers, leafhoppers and aphids. Approximately 270 Water Scorpion species have been described worldwide, 13-15 of which inhabit North America.  No doubt many others are awaiting “discovery”. 

Physical Description

The body of the Brown Water Scorpion resembles that of a terrestrial stick insect and is yellowish-tan to dark brown in color.  Others, including those in the North American genus Nepa, are flattened in appearance.  The front legs are raptorial (designed for grasping) and superficially similar to those of a praying mantis.  Unlike a mantis, however, the terminal segments of the Water Scorpion’s front legs fit into a groove when not in use, and swing out like folding knives when needed.  These hook-like leg tips can be seen in the photo showing a Water Scorpion poised just below a guppy.

The middle and hind legs are about as long as the body, and paired breathing tubes are situated at the end of the abdomen.  This species reaches 1.75 inches in length (to approximately 3 inches including the breathing tube).

Water Scorpions can fly, but do so only rarely.

Amazing Organs

Three pairs of disc-shaped organs on the abdomen, known as false spiracles, enable Water Scorpions to gauge water depth and compensate for changes in water pressure.


From southern Canada through much of the continental USA to northern Mexico. 


Poorly adapted for swimming, Water Scorpions favor the still waters of ponds, swamps, lake edges and canals, where they remain immobile among plants and sticks.  The photo of my nephew “waiting in ambush” shows their typical habitat. 


Water Scorpion predatory hooksThis voracious carnivore feeds largely upon the body fluids of invertebrates, but will also take small tadpoles, fishes and newts.  Water Scorpions are ambush predators, relying upon camouflage when hunting.  They lash out with the front legs and subdue prey via salivary fluids injected through the sharp beak.  These fluids contain chemicals that tranquilize prey and initiate digestion; food is consumed in liquid form, in the manner of spiders.


Eggs are inserted into living or dead plants, and hatch in 2-4 weeks.  The nymphs resemble the adults (incomplete metamorphosis) and mature in 4-6 weeks.

Captive Care


The aquarium should be covered and the water slow-moving.  Water Scorpions are poorly-equipped for swimming, and will perish if buffeted by strong currents. 

The tank should be well-stocked with plants (preferably live) and sticks that rise to the water’s surface.   Water Scorpions breathe by extending the abdominal breathing tubes above the water’s surface, and cannot utilize oxygen dissolved in the water. They will not thrive if unable to station themselves on a plant or stick near the water’s surface.

Filtration and Water Quality

Water Scorpions may be kept in an unfiltered bowl, jar, or aquarium if provided a weekly water change (please see photo of my simple enclosure).  Live plants will enhance the aquarium’s appearance and assist in maintaining water quality.  If filtration is desired, be sure to avoid strong water currents.  Sponge, undergravel, and corner filters are ideal.

Although Water Scorpions inhabit waters that are often subjected to varying pH and ammonia levels, water quality should not be ignored. In this regard, they should be maintained as are tropical fishes (please write in if you need further information).  Water used in the aquarium should be treated with chlorine/chloramine removal drops and maintained at pH 6.8-7.2. 

Light, Heat and Water Quality

Temperatures of 65-82 F are well-tolerated.


Water Scorpions are attracted to prey by movement, and will take small crickets and bits of fish, shrimp and earthworm from tongs.  I also offer small guppies, mosquito larvae and blackworms.  I’ve not seen them take smaller prey items, but mosquito larvae do disappear (and seem not to be buzzing about the house!). 

Compatible Species

In common with many aquatic insects, Water Scorpions will consume smaller individuals of their own species.  However, as captive breeding seems not to have been recorded, keeping several in a well-planted aquarium would be worthwhile (reduced temperatures and a shortened light cycle in winter may encourage reproduction). 

These slow, deliberate hunters will not get enough food in aquariums housing diving beetles, water boatmen, fishes and other aggressive feeders.  In such situations, they must be individually fed via tongs.

Captive Longevity

Adults over-winter and can live for 2 – 2.5 years.


Child with Water ScorpionAs you can see from my 4-year-old nephew’s smiling face, Water Scorpions are rather “stiff” and cannot bite if held as illustrated.  The long beak seems quite formidable, but several observers report that it cannot pierce human skin (this re Brown Water Scorpions; others not mentioned).  I’m wary of aquatic insects, however, as even the smallest predatory species can usually inflict a painful bite.  After so many decades of being bitten and stung by creatures large and small, I have no desire to experiment!  I advise that you handle via tongs or a net. 

What Can I Do?

Insects and other invertebrates occupy every conceivable aquatic habitat, from birdbaths to swamps and even the sea.  Running a net or small strainer through just about any bit of available water will yield a treasure trove of interesting creatures, many of which are quite easy to keep and even breed.  So get out there and look around, and please feel free to write in with suggested topics, so that I can cover your favorite species.

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio


Further Reading

 Diving Beetle Care

Video: Australian Water Scorpion

Water Scorpion Natural History and videos  

Insect Families in the Order Hemiptera

American Box Turtles as Pets – Care and Natural History

Male Eastern Box TurtleHello, Frank Indiviglio here.  The beautifully-patterned American Box Turtles (Terrapene spp.) are very popular among reptile enthusiasts worldwide. They are extremely responsive, intelligent, calm, and may live for 60-100 years…what more could a turtle fan want!  Unfortunately, there are many misconceptions concerning their care.  The following information will enable you to meet their needs…please post any specific questions you may have.

Note: Box Turtle populations have declined drastically. In addition to habitat loss and road-kill, many were exported to foreign pet markets when European tortoises were protected by law.  Please purchase only captive-bred animals.

Natural History

Four Box Turtle species the Eastern, Spotted, Ornate and Coahuilan – range from southern Canada through most of the USA and into Mexico.  Ten uniquely-colored subspecies, including the Florida, Gulf Coast and Yucatan Box Turtles, are also recognized. 

Box Turtles frequent woodlands, marshes, fields, agricultural land, and many other habitats.  Some, such as the Eastern Box Turtle (T. carolina), are largely terrestrial, while Three-Toed Box Turtles (T. carolina triunguis) and others split their time between land and shallow water.  The Coahuilan Box Turtle (T. coahuila), the group’s only truly aquatic member, is found only in Mexico’s Cuatro Cienegas Basin.  Several of my colleagues at the Bronx Zoo studied this species in the wild, and I had the good fortune to work with a breeding group for many years; please look for my future article on this most unique turtle.

Although certain other turtles posses shell hinges that allow the plastron (lower shell) to be drawn up (“like a box”), in no group is this ability so well developed as the American Box Turtles (please see photo). Read More »

Green Sea Turtles Die on Farm – Do Meat-Trade Turtles Aid Conservation?

Green Sea TurtleHello, Frank Indiviglio here.  An accident that caused the deaths of 299 endangered Green Turtles at the Cayman Turtle Farm has raised concerns about the facility’s operation. The incident brought other issues to my mind as well.  I was first inspired by the legendary herpetologist Archie Carr, and have since been involved in several field studies of Green, Leatherback and other marine turtles (please see article below).  I see the value in organizations such as Cayman Turtle Farm, which raises turtles for the food market while also racking up important “firsts” in breeding and research.  However, many disagree with me.  What’s your opinion?  Any comments you may wish to post below would be much appreciated.

Conservation through Commercialization

Whatever your personal feelings concerning the consumption of turtles or other animals may be, it is clear that commercial farming can play a role in Chinese Softshellconservation. The classic US example is the American Alligator.  Legal protections helped, of course, but large scale breeding for the meat and hide trade made a huge difference in that species’ future.  Read More »

Green Anaconda Relatives – Bolivian, Dark-Spotted and Yellow Anacondas

Hello, Frank Indiviglio here.  The massive Green Anaconda (Eunectes murinus) is one of the world’s best-known snakes.  I had the good fortune of participating in the first long-term study of this species in the wild (please see this article), and zoos have kept and bred them for decades.  But its relatives, despite being large, impressive creatures, have not been well studied.  One, the Bolivian Anaconda (E. beniensis), was only described in 2002, and its natural history remains shrouded in mystery; we know only a bit more about the Dark-Spotted Anaconda (E. deschauenseei).  The Yellow Anaconda (E. notaeus) regularly appears in zoos and the pet trade, but field studies are lacking.

Dark-Spotted or De Schauensee’s Anaconda, Eunectes deschauenseei

Although described as a distinct species back in 1936, the habits of the Dark-Spotted Anaconda remain unstudied, and it rarely appears in public collections.  While working with Green Anacondas in Venezuela, I tried to arrange a side trip to an area where they were reported to live, but was unable to arrange it.  A review of the acquisition records at the Bronx Zoo, where I worked for many years, revealed that several specimens were believed to be this species, but none were definitely identified as such.  I recently poked around among stored Green Anacondas in the collection of the American Museum of Natural History (courtesy of a colleague there) and hope to return to check on Dark-Spotted Anacondas.  Although widely separated in range from the Yellow Anaconda, many taxonomists hold that the two are closely related. Read More »

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